Differential air pressure systems and methods of using and calibrating such systems for mobility impaired users

ABSTRACT

Described herein are various embodiments of differential air pressure systems and methods of using and calibration such systems for individuals with impaired mobility. The differential air pressure systems may comprise an access assist device configured to help a mobility impaired user to stand in a pressure chamber configured to apply a positive pressure on a portion of the user&#39;s body in the seals pressure chamber. The system may further comprise load sensors configured to measure the user&#39;s weight exerted inside and outside the chamber. The system may be calibrated by determining a relationship between the actual weight of the user and the pressure in the chamber, where the actual weight of the user may be measured by more than one load sensor and at least one load sensor is not in the chamber.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit to U.S. Application No. 61/454,432 filedon Mar. 18, 2011.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD

Described herein are various embodiments of differential air pressuresystems for use by individuals with impaired mobility and methods ofcalibrating and using such systems.

BACKGROUND

Methods of counteracting gravitational forces on the human body havebeen devised for therapeutic applications as well as physical training.Rehabilitation from orthopedic injuries or neurological conditions oftenbenefits from precision unweighting (i.e. partial weight bearing)therapy. One way to counteract the effects of gravity is to suspend aperson using a body harness to reduce ground impact forces. However,harness systems may cause pressure points that may lead to discomfortand sometimes even induce injuries. Another approach to counteract thegravity is to submerge a portion of a user's body into a water-basedsystem and let buoyancy provided by the water offset gravity. However,the upward supporting force provided by such water-based systemsdistributes unevenly on a user's body, varying with the depth of theuser's body from the water surface. Moreover, the viscous drag of thewater may substantially alter the muscle activation patterns of theuser.

Differential Air Pressure (DAP) systems have been developed to use airpressure in, for example, a sealed chamber to simulate a low gravityeffect and support a patient at his center of gravity without thediscomfort of harness systems or the inconvenience of water-basedtherapies. DAP systems generally utilize a chamber for applyingdifferential air pressure to a portion of a user's body, but in order touse these systems, a user must first be able to access the chamber,which may require stepping or climbing over one or more portions of thesystem. In some instances, an individual may have limited or low degreeof mobility which may hinder his ability to access the chamber. Forexample, patients who have suffered a stroke or physical injury may bewheelchair-bound or bedridden and unable to walk or stand independentlywithout a great deal of assistance. Similarly, patients who have alesser degree of impairment such as muscle strain or a sprain may alsorequire a moderate amount of assistance to enter, stand in, and exit thechamber. Accordingly, these patients with varying levels of impairedmobility may not be able to take advantage of the many benefits ofdifferential air pressure therapy because of the difficulty in gettingin and out of the systems. As such a need exists for a DAP system thatallows patients with varying degrees of impaired mobility to access anduse DAP therapy systems.

In addition, another obstacle to providing treatment for the mobilityimpaired user is the proper calibration of a DAP system for the disableduser. A DAP system is often calibrated for each user prior to initiatingtherapy. In the past, calibration of DAP systems has relied on theability to weigh the patient on a ground mounted horizontal surfacescale which required the patient to stand still on their feet duringcalibration for several minutes. Such calibration methods may be usedfor patients with a high degree of mobility requiring none or minimumassistance, but are difficult or impossible to employ for individualswho require greater assistance, especially for those who cannot beartheir own weight upright. Although DAP systems can be used even withmobility impaired individuals without calibration, calibration improvesthe precision of the treatment and provides personalized therapy for theuser. A calibrated DAP system can deliver precise, repeatableunweighting regimes and therapies accurate to 1% of patient weight.Precision is desirable as it allows clinicians and doctors to control atreatment and rehabilitation protocol with great specificity to delivermaximum rehabilitation effectiveness. As such, there is a need for acalibration system and method for allowing calibration of a DAP systemwhere the user requires weight support assistance during the calibrationprocedure.

SUMMARY OF THE DISCLOSURE

The present invention relates to differential air pressure systems thatprovide therapeutic conditioning and training for individuals withimpaired mobility. Included in this description are methods and devicesconfigured to assist users with impaired mobility in entering, exiting,and using differential air pressure systems.

Some embodiments described provide a differential air pressure (DAP)system with an access assist device designed to improve mobility of adisabled individual. These differential pressure systems may include apressure chamber with a seal interface configured to receive a portionof a disabled user's body and to form a seal between the user's body andthe chamber, the chamber is configured to apply pressure to the portionof the user's body while the user's body is sealed in the chamber; anexercise device can be placed in the pressure chamber, where theexercise device is configured to contact the user's body while theexercise device is in operation; a first load sensor is coupled to theexercise device, the first load sensor configured to measure the loadapplied by the user to the exercise device while the user is in thechamber and provide an output signal; a second load sensor is coupled tothe differential pressure system at a position that is different thanthe first load sensor and configured to provide an output signal.

Optionally, in any of the preceding embodiments, a processor may beconfigured to receive the output signals from the load sensors and tocalibrate the system for use by the disabled user.

Additionally, in any of the preceding embodiments, calibrating thesystem may entail generating a relationship between pressure in thechamber and actual weight of the user while the user is sealed in thechamber, wherein the actual weight of the user is the total load ortotal user weight measured by the first and second load sensors atpressure points, the processor regulating the pressure of the chamberaccording to said relationship.

Optionally, in any of the preceding embodiments, the DAP system mayfurther comprise an access assist device configured to assist thedisabled user's access to the chamber. Additionally, in any of thepreceding embodiments, the second load sensor may be in communicationwith the access assist device. Additionally, in any of the precedingembodiments, the second load sensor may be positioned on the accessassist device.

Optionally, in any of the preceding embodiments, the access assistdevice is configured to vertically adjust the user's position relativeto the chamber. Optionally, in any of the preceding embodiments, theaccess assist device is configured to bear a portion of the user'sweight during calibration.

Additionally, in any of the preceding embodiments, the access assistdevice is configured to bear substantially all of the user's weightduring calibration.

Optionally, in any of the preceding embodiments, the DAP system mayfurther have a plurality of load sensors coupled to the pressure chamberand configured to engage the portion of the user's body sealed in thepressure chamber and a plurality of load sensors coupled to thedifferential pressure system and configured to engage the user's bodyoutside the sealed interface of the pressure chamber.

Optionally, in any of the preceding embodiments, the DAP system has afirst load sensor positioned within the pressure chamber and isconfigured to engage the portion of the user's body in the pressurechamber, and a second load sensor positioned outside the pressurechamber and the second load sensor is configured to engage the user'sbody outside the pressure chamber.

Optionally, in any of the preceding embodiments, the DAP system includesa treadmill comprising a runway belt and a load sensor under the runwaybelt.

Optionally, in any of the preceding embodiments, calibrating the systemincludes using an actual weight of the user which is provided by thetotal load or total user weight measured by the plurality of loadsensors coupled to the pressure chamber and configured to engage theportion of the user's body sealed in the pressure chamber and aplurality of load sensors coupled to the differential pressure systemand configured to engage the user's body outside the sealed interface ofthe pressure chamber.

Optionally, in any of the preceding embodiments, the DAP system includeshandrails outside the pressure chamber. Additionally, the handrails maybe optionally configured to bear the user's weight anywhere along thelength of the handrail. Load sensors may be mounted or removablyconnected to the handrail to measure the amount of weight supported bythe handrails.

Optionally, in any of the preceding embodiments, the DAP system has aseal frame supporting the seal of the pressure chamber and configured tosupport the weight of the user, wherein the second load sensor measuresthe weight supported during supported during calibration.

Additionally, in any of the preceding embodiments, the DAP system caninclude a frame assembly that the disabled user's weight duringcalibration and a load sensor measures the amount of weight borne by theframe assembly.

Optionally, in any of the preceding embodiments, the access assistdevice can include a user connection configured to adjust the positionof the disabled user relative to the seal of the chamber.

Optionally, in any of the preceding embodiments, the access assistdevice can include a hoist device. Additionally, the access assistdevice can use a harness assembly designed to be worn by the user. Inother variations, the access assist device can include an overheadsuspension device.

Other embodiments described herein provide for a DAP system forimproving mobility of a disabled individual only able to stand withassistance where the DAP system has a pressure chamber with a sealinterface configured to receive a portion of a disabled user's body andto form a seal between the user's body and the chamber; a blower andvalve control system configured to apply pressure to the portion of theuser's body while the user's body is sealed in the chamber; an exercisedevice within the pressure chamber, wherein the exercise device isconfigured to contact the user's body while a portion of the user's bodyis within the seal interface; an access assist device configured toassist the disabled user's ingress and egress to the chamber; a firstload sensor positioned in the pressure chamber below the user's torsoand configured to measure the weight of the user in the chamber andcommunicate the measurements to a processor; a second load sensorpositioned on the system outside the pressure chamber and configured tomeasure the weight of the user exerted on the access assist device andcommunicate the measurements to a processor; a processor configured toreceive weight input from inside and outside the pressure chamber,wherein the processor calibrates the system for the user system bygenerating a relationship between pressure in the chamber and actualweight of the user, wherein the actual weight of the user is provided bythe total weight measured by the load sensors at pressure points, theprocessor regulating the pressure of the chamber according to saidrelationship.

Optionally, in any of the preceding embodiments, the load sensors can beplaced on the access assist device.

In further variations, the access assist device comprises a supportframe attached to the system and configured to support a portion of thedisabled user's weight while the user is upright.

Optionally, in any of the preceding embodiments, the support frame isdetachable from the system. In some variations, the support frame is adetachable support bar and can electronically communicate wirelessly orthrough a wired connection with the processor.

Additionally, in any of the preceding embodiments, the access assistdevice vertically and horizontally adjusts the position of the disableduser.

Optionally, in any of the preceding embodiments, the DAP system includesan interlocking mechanism configured to engage with at least one of thevertical adjustment or the horizontal adjustment of the access assistdevice, wherein the processor is configured to engage the interlockingmechanism to stop movement of the access assist device. In othervariations, the interlocking mechanism comprises at least one interlockcheckpoint at which the interlocking mechanism can engage if the chamberis not configured to receive the user.

Additionally, in any of the preceding embodiments, the access assistdevice supports at least a portion of the user's weight prior tocalibration and provides substantially no weight support to the userfollowing calibration. The access assist device can also optionallyprovide no weight support during calibration. Additionally, the accessassist device may provide the user substantially no weight support whilethe chamber is pressurized and the exercise device is operating.

Optionally, in any of the preceding embodiments, the DAP system furtherincludes at least one performance sensor for measuring a performanceparameter of the user while the user is moving in contact with theexercise device.

Optionally in any of the preceding embodiments, the access assist devicecomprises a waist support device.

Optionally in any of the preceding embodiments, the access assist deviceis a motorized lift.

In another variation, the DAP system includes a pressure chamber with aseal interface configured to receive a portion of a disabled user's bodyand to form a seal between the user's body and the chamber, the chamberconfigured to apply pressure to the portion of the user's body while theuser's body is sealed in the chamber; an exercise device placed in thepressure chamber, wherein the exercise device is configured to contactthe user's body while the exercise device is in operation; a load sensorcoupled to the exercise device, the load sensor configured to measurethe weight applied by the user to the exercise device while the user isin the chamber and to provide an output signal for weight measurements;a calibration device configured to measure the weight of the user bodyexerted outside the pressure chamber, the calibration device providingan output signal for weight measurements; and a processor configured toreceive the output signals from the load sensor and the calibrationdevice to calibrate the system for use by the disabled user bygenerating a relationship between pressure in the chamber and actualweight of the user while the user is sealed in the chamber, wherein theactual weight of the user is the total load or total user weightmeasured by the load sensor and the calibration device at pressurepoints, the processor regulating the pressure of the chamber accordingto said relationship.

Additionally, in any of the preceding embodiments, at least one loadsensor can be placed on the seal interface of the chamber.

Optionally, in any of the preceding embodiments, the calibration deviceis a support frame configured to support at least a portion of theuser's weight during calibration. In some embodiments, the support frameis configured to allow the user to lean against the frame. In furthervariations, the support frame comprises at least one load sensor formeasuring the weight exerted against the support frame duringcalibration. Optionally, in any of the preceding embodiments, thesupport frame can be a handrail or arm rest.

Optionally, in any of the preceding embodiments, the support frame isremovable following calibration.

Optionally, in any of the preceding embodiments, the load sensor is partof a removable adjustable pad that can be attached to the support frameof an access assist device or the frame assembly of the DAP system.

Optionally, in any of the preceding embodiments, a portion of thesupport frame is inside the pressure chamber.

Optionally, in any of the preceding embodiments, the support frame is anoverhead handlebar.

Optionally, in any of the preceding embodiments, the DAP system caninclude a height adjustable seal frame configured to receive and supporta portion of the user's body. In some embodiments, the seal frame isheight adjustable by way of a motorized lift configured to raise andlower the seal frame and generate an output signal reading the weight ofthe user raised or lowered by the motorized lift device.

Optionally, in any of the preceding embodiments, the calibration deviceis a support bar that can be removably inserted into a receiving channelon the system. The support bar can include circuitry allowing the bar tocommunicate with the processor. Optionally, in any of the precedingvariations, the support bar can store user related data.

Additionally, in other variations, the support bar is detachable from asupport bar receiver on the DAP system, where the support receiver isconfigured to measure the weight of the user exerted against the supportbar.

Other embodiments herein also provide for a method of calibrating adifferential pressure system for a disabled user with impaired mobilityby supporting a portion of the user's weight with a calibration device;supporting another portion of the user's weight inside a sealed pressurechamber; sealing the chamber around an area of the user's body; andcalibrating the differential pressure system for the disabled user basedon the total weight supported.

Additionally, in any of the preceding embodiments, the method ofcalibrating includes detecting whether a calibration device has beenconnected to the system.

Additionally, in any of the preceding embodiments, the method ofcalibrating includes detecting that the calibration device has beendisengaged from the system.

Optionally, in any of the preceding embodiments, load sensors can beconfigured to communicate wirelessly or through a wired path with theprocessor.

Other embodiments provide for a method of calibrating the differentialpressure system by supporting at least a portion of the user weight in apressure chamber with an access assist device having an assist deviceload sensor configured to measure the weight supported by the assistdevice while the user is in the pressure chamber; sealing the chamberaround an area of the user's body; and calibrating the differentialpressure system for the disabled user based on the total load or totaluser weight measure by the load sensor.

Optionally, in any of the preceding embodiments, the method ofcalibrating includes measuring the weight of the user using a loadsensor in the pressure chamber; and calibrating the differentialpressure system by measuring the total weight input from all the loadsensors at different pressure levels.

Additionally, in any of the preceding embodiments, calibration includesgenerating a relationship between the pressure in the chamber and theactual weight of the user. In some embodiments, the actual weight of theuser is the total load or total user weight measured by the load sensorsin the access assist device and the chamber.

An additional method of calibrating includes lifting a user relative toan opening in a pressure chamber with an access assist device; loweringthe user into the opening such that a portion of the user's body is inthe pressure chamber; sealing the chamber around the portion of thepatient's body; outputting a signal from a load sensor in the pressurechamber; outputting a signal from a load sensor coupled to the accessassist device; and calibrating the differential pressure system for thedisabled user based on the total load or total user weight measured byan output from a load sensor coupled to the pressure chamber and anoutput from the load sensor coupled to the access assist device.

Optionally, in any of the preceding embodiments, the system may have apressure sensor in the chamber that outputs a signal on pressure in thechamber. Additionally, the pressure in the chamber may be regulatedaccording to a relationship between pressure and the total load or totaluser weight measured from the load sensors at pressure points.

Other embodiments provide for a differential pressure system forimproving mobility of a disabled individual, with a pressure chamberwith a seal interface configured to receive a portion of a disableduser's body and to faun a seal between the user's body and the chamber,the chamber configured to apply pressure to the portion of the user'sbody while the user's body is sealed in the chamber; a platform in thepressure chamber, wherein the platform is configured to contact theuser's body; a first load sensor positioned substantially underneath theuser's torso and configured to measure the load applied by the userwhile the user is in the chamber and to provide an output signal; asecond load sensor coupled to the differential pressure system at aposition that is different from the first load sensor, the second loadsensor configured to provide an output signal; a processor configured toreceive the output signals from the load sensors and to calibrate thesystem for use by the disabled user by generating a relationship betweenpressure in the chamber and actual weight of the user while the user issealed in the chamber, wherein the actual weight of the user is thetotal weight of the user measured by the first and second load sensorsat pressure points, the processor regulating the pressure of the chamberaccording to said relationship.

In any of the preceding embodiments, the system may optionally includean access assist device configured to assist the disabled user's accessto the chamber, wherein the second load sensor is in communication withthe access assist device. Additionally, the second load sensor may bepositioned on the access assist device. Optionally, in any of thepreceding embodiments, the access assist device is configured to bear aportion of the user's weight during calibration. Optionally, in any ofthe preceding embodiments, the access assist device is configured tobear substantially all of the user's weight during calibration.

Additionally, the system can include, optionally, a plurality of loadsensors substantially underneath the user's torso and a plurality ofload sensors coupled to the differential pressure system at one or morelocations above the user's lower extremities. In some embodiments, thefirst load sensor is positioned within the pressure chamber and isconfigured to engage the portion of the user's body in the pressurechamber, and the second load sensor is positioned outside the pressurechamber and is configured to engage the user's body outside the pressurechamber. Optionally, in any of the preceding embodiments, the systemcomprises an actual weight of the user provided by the total user weightmeasured by the plurality of load sensors at a pressure point.Additionally, in any preceding embodiments, the total weight of the useris determined by summing the load measured by the first and secondsensors and subtracting a baseline load measurement from the sum.

Optionally, in the any of the preceding embodiments, the system canfurther include a handrail outside the pressure chamber wherein thehandrail is configured to bear a portion of the user's weight and thesecond load sensor measures the amount of the user's weight supported bythe handrail during calibration.

Optionally, in any of the preceding embodiments, the system can furthercomprise a seal interface frame supporting the seal interface of thepressure chamber and configured to support the weight of the user,wherein the second load sensor measures the amount of the user's weightsupported by the seal interface frame during calibration.

Optionally, in any of the preceding embodiments, the system can furthercomprise a frame assembly, wherein the frame assembly bears a portion ofthe disabled user's weight during calibration and the second load sensormeasures the amount of the user's weight supported by the frame assemblyduring calibration.

Optionally, in any of the preceding embodiments, the access assistdevice comprises an overhead suspension device.

Optionally, in any of the preceding embodiments, the access assistdevice is a handrail, motored lift, or a support that is removablyattachable to a frame on the system. Additionally, in any of thepreceding embodiments, the support bar comprising an attachmentmechanism to removably attach and detach the bar from the frame. Thesupport bar can also output a measured load signal to the processor.Optionally, in any of the preceding embodiments, the support bar isconfigured to store user-related data. Optionally, in any of thepreceding embodiments, the system further comprising a support barreceiver, wherein the support receiver is configured to measure theweight of the user exerted against the support bar while the support baris attached to the system.

Optionally, in any of the preceding embodiments, any load sensor can beconfigured to communicate wirelessly, through wired connection, and/orboth with the system or processor.

Optionally, in any of the preceding embodiments, the plurality of loadsensors coupled to the system above the user's lower extremities arepositioned on the system at a distance within the user's arm span.

Other embodiments provide a differential pressure system for improvingmobility of a disabled individual, comprising a pressure chamber with aseal interface configured to receive a portion of a disabled user's bodyand to form a seal between the user's body and the chamber, the chamberconfigured to apply pressure to the portion of the user's body while theuser's body is sealed in the chamber; an exercise device placed in thepressure chamber, wherein the exercise device is configured to contactthe user's body while the exercise device is in operation; at least oneload sensor on the exercise device, the load sensor configured tomeasure the load applied by the user to the exercise device while theuser is in the chamber and to provide an output signal; at least oneload sensor not on the exercise device and positioned on thedifferential pressure system above the user's lower extremities, theload sensor configured to provide an output signal; a processorconfigured to receive the output signals from the load sensors and tocalibrate the system for use by the disabled user by generating arelationship between pressure in the chamber and actual weight of theuser while the user is sealed in the chamber, wherein the actual weightof the user is the total user weight measured by the load sensors atpressure points, the processor regulating the pressure of the chamberaccording to said relationship.

Optionally, in any of the preceding embodiments, the exercise device isa treadmill comprising a runway belt and the load sensor on the exercisedevice is under the runway belt.

Optionally, in any of the preceding embodiments, the load sensor not onthe exercise device is positioned on the access assist device.

Other embodiments provide for a method of calibrating a differentialpressure system for a disabled user with impaired mobility comprisingsupporting at least a portion of the user's weight with an access assistdevice having an assist device load sensor configured to measure theuser's weight supported by the assist device; positioning the user in apressure chamber; sealing the chamber around an area of the user's body;and calibrating the differential pressure system for the disabled userbased on the total user weight measured by the load sensor.

Optionally, in any of the preceding embodiments, calibrating furthercomprises calculating the total user weight by subtracting a baselineload measurement from the total load measured by the sensor. Optionally,in any of the preceding embodiments, calibrating further compriseszeroing the load sensor prior to supporting the user's weight.Optionally, in any of the preceding embodiments, calibrating furthercomprises supporting a portion of the user's weight from underneath theuser's torso while the user is in the chamber, the chamber having achamber load sensor to measure the supported user weight and calibratingthe system based on the total user weight measured from the loadsensors.

Another method of calibrating comprises lifting a user relative to anopening in a pressure chamber with an access assist device; lowering theuser into the opening such that a portion of the user's body is in thepressure chamber; sealing the chamber around the portion of thepatient's body; outputting a signal from a load sensor in the pressurechamber; outputting a signal from a load sensor coupled to the accessassist device; and calibrating the differential pressure system for thedisabled user based on the total user weight measured by an output fromthe load sensor in the pressure chamber and an output from the loadsensor coupled to the access assist device. Optionally, in any of thepreceding embodiments, the total user weight is calculated bysubtracting a baseline load measurement from the total load measured bythe load sensors while the user is sealed in the chamber.

Other embodiments provide for a differential pressure system forimproving the mobility of a disabled individual comprising: a pressurechamber with a seal interface configured to receive a portion of adisabled user's body and to form a seal between the user's body and thechamber, the chamber configured to apply pressure to the portion of theuser's body while the user's body is sealed in the chamber; an exercisedevice placed in the pressure chamber, wherein the exercise device isconfigured to contact the user's body while the exercise device is inoperation; a load sensor coupled to the exercise device, the load sensorconfigured to measure the weight applied by the user to the exercisedevice while the user is in the chamber and to provide an output signalfor weight measurements; a calibration device configured to measure theweight of the user's body exerted outside the pressure chamber, thecalibration device providing an output signal for weight measurements;and a processor configured to receive the output signals from the loadsensor and the calibration device to calibrate the system for use by thedisabled user by generating a relationship between pressure in thechamber and actual weight of the user while the user is sealed in thechamber, wherein the actual weight of the user is the total user weightmeasured by the load sensor and the calibration device at pressurepoints, the processor regulating the pressure of the chamber accordingto said relationship.

Optionally, in any of the preceding embodiments, the calibration deviceis a support bar configured to removably attach to the system outsidethe pressure chamber. Optionally, in any of the preceding embodiments,the calibration device comprises a load sensor. Optionally, in any ofthe preceding embodiments, the calibration device supports a portion ofthe user's weight during calibration.

Other embodiments provide a differential air pressure system comprisinga positive pressure chamber with a seal interface configured to receivea portion of a user's body and form a seal between the user's body andthe chamber; a lift access device comprising a hoist device and a loadsensor, wherein the load sensor outputs a load measurement when liftinga user; a load sensor attached a bottom portion of the pressure chamber,wherein the load sensor outputs a load measurement when a user is in thesealed chamber; and a processor configured to calibrate the system byreceiving the load measurements from the load sensors, calculating thetotal user weight supported by the lift access device and chamber atpressure points, and generating a pressure weight relationship.

Additionally, in any of the preceding embodiments, the system mayinclude an interlocking mechanism configured to engage with the liftaccess device, wherein the processor is configured to engage theinterlocking mechanism to stop movement of the lift access device.Optionally, the interlocking mechanism comprises at least one interlockcheckpoint at which the interlocking mechanism can engage if the chamberis not configured to receive the user.

Other embodiments provide for a method of improving cardiovascularfunction in a paralyzed user comprising lifting the paralyzed user;lowering and sealing the user into a pressure chamber of a differentialpressure system; supporting a portion of the user's body such that theuser is substantially upright; sealing the pressure chamber; calibratingthe differential pressure system to generate a pressure-weightrelationship; and regulating the pressure in the chamber according tothe relationship.

Other embodiments provide for a method of improving a stroke patient'smotor skills comprising supporting a portion of the patient's weightwith a calibration device; supporting another portion of the patient'sweight inside a sealed pressure chamber; sealing the chamber around anarea of the patient's body; calibrating the differential pressuresystem; and regulating the pressure in the chamber according to therelationship.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of various features and advantages of theembodiments described herein may be obtained by reference to thefollowing detailed description that sets forth illustrative examples andthe accompanying drawings of which:

FIG. 1A is a block diagram schematically illustrating one example of adifferential air pressure system according to one embodiment.

FIG. 1B is a flow diagram schematically illustrating a method forcalibrating the system of FIG. 1 A in accordance with one embodiment.

FIG. 2A is a perspective view of one example of a differential airpressure system;

FIG. 2B is a top view of the system of FIG. 2A;

FIG. 2C is a perspective component view of the system of FIG. 2A.

FIGS. 3A and 3B are schematic illustrations of a middle panel and a sidepanel of one example of a pressure chamber, respectively.

FIGS. 4A and 4B illustrate one embodiment of a pressure chamber, FIG. 4Ais a frontal view of the pressure chamber and FIG. 4B is the top view ofthe chamber in FIG. 4A.

FIG. 5 is a perspective view of one embodiment of a pressure chamberattached to the base of a differential air pressure system.

FIGS. 6A and 6B are schematic anterior and posterior perspective views,respectively of another embodiment of a pressure chamber in an expandedstate;

FIG. 6C is a schematic anterior perspective view of the pressure chamberof FIG. 6A and FIG. 6B in a collapsed state.

FIG. 7A is a perspective view of one example of a differential airpressure system. FIGS. 7B-7E are side views of the system of FIG. 7A.

FIGS. 8A-8C is a perspective view of the differential air pressuresystem of FIG. 2A with an access assist device removably attached.

FIG. 9 shows one embodiment of a supportive bar that can provide accessand calibration assistance.

FIG. 10 shows another embodiment of a supportive bar that can provideaccess and calibration assistance.

FIG. 11 shows an embodiment of a supportive structure with two barportions to provide access and calibration assistance.

FIG. 12 shows an embodiment with a supportive bar attached to the sealframe of the differential air pressure system.

FIGS. 13A-13E show various embodiments of a supportive leaning structurewith various load cell configurations.

FIG. 14 is a flow diagram schematically illustrating a method forcalibrating the system according to one embodiment.

FIG. 15 is a flow diagram schematically illustrating a method forinterlocking the system according to one embodiment.

FIG. 16A shows a side view of a differential pressure system with amotorized lift according to one embodiment.

FIG. 16B shows a side view of a differential pressure system with amotorized lift and a wheelchair ramp according to one embodiment.

FIGS. 17A-17C show an access assist device according to one embodimentfor moving a user into a differential pressure system.

FIGS. 18A-18B show another access assist device according to oneembodiment for moving a user into a differential pressure system.

FIG. 19 shows another access assist device according to one embodimentfor moving a user into a differential pressure system with an overheadsuspension system.

FIG. 20 is a flow diagram schematically illustrating a method forcalibrating the system according to one embodiment.

FIG. 21 is a flow diagram schematically illustrating a method forcalibrating the system according to one embodiment.

DETAILED DESCRIPTION

Described here are differential air pressure (DAP) systems designed tobe used by individuals with impaired mobility. Generally, DAP systemsutilize changes in air pressure to provide positive or negative weightsupport for training and rehabilitation systems and programs. Variousexamples of DAP systems are described in International PatentApplication Serial No. PCT/US2006/038591, filed on Sep. 28, 2006, titled“Systems, Methods and Apparatus for Applying Air Pressure on A Portionof the Body of An Individual,” International Patent Application SerialNo. PCT/US2008/011807, filed on Oct. 15, 2008, entitled “Systems,Methods and Apparatus for Calibrating Differential Air PressureDevices,” International Patent Application Serial No. PCT/US2008/011832,filed on Oct. 15, 2008, entitled “Systems, Methods and Apparatus forDifferential Air Pressure Devices,” and International Patent ApplicationSerial No. PCT/US2010/034518, filed on May 12, 2010, entitled“Differential Air Pressure Systems,” all of which are herebyincorporated by reference in their entirety.

In some embodiments described herein, the DAP systems comprise a chamberfor receiving at least a portion of a user's body and an access assistdevice for facilitating user access to the chamber. FIG. 1 Aschematically illustrates one example of a DAP system 100, comprising asufficiently airtight chamber 102 which houses an optional exercisesystem 112. The chamber 102 includes a user seal 104 configured toreceive a user 101 and to provide a sufficient airtight seal with theuser's lower body 106.

A pressure control system 103 is used to generate alter the pressurelevel (P2) inside the chamber 102 relative to the ambient pressureoutside the chamber (P1). When a user positioned in the DAP system issealed to the chamber 102 and the chamber pressure (P2) is changed, thedifferential air pressure (ΔP=P2−P1) between the lower body 106 of theuser 101 inside chamber 102 and the upper body outside the chamber 102generates a vertical force acting through the seal 104 and also directlyonto the user's lower body 106. If the chamber pressure P2 is higherthan the ambient air pressure P1, there will be an upward vertical force(Fair) that is proportionate to the product of the air pressuredifferential (ΔP) and the cross-sectional area of the user seal 110. Theupward force (Fair) may counteract gravitational forces, providing apartial body-weight-support that is proportional to the air pressuredifferential (ΔP). This weight support may reduce ground impact forcesacting on the joints, and/or reduce muscular forces needed to maintainposture, gait, or other neuromuscular activities, for example.

The chamber 102 may be attached to a platform or base 108 that supportsthe chamber 102 and the exercise machine 112. The exercise machine 112may be at least partially or wholly housed within the chamber 102. Anyof a variety of exercise machines may be used, e.g., a treadmill, astepper machine, an elliptical trainer, a balance board, and the like.Other exercise machines that may be used also include seated equipment,such as a stationary bicycle or a rowing machine. Weight support withseated equipment may be used to facilitate physical therapy or exercisein non-ambulatory patients, including but not limited to patients withpressure ulcers or other friable skin conditions located at the ischialtuberosities or sacral regions, for example. The exercise system ormachine 112, such a treadmill, may have one or more adjustmentmechanisms (e.g., workload, height, inclination, and/or speed), whichmay be controlled or adjusted by the DAP system console, or maycontrolled separately. Other features, such as a heart rate sensor, mayalso be separately managed or integrated with the DAP console. Those ofordinary skill in the art will appreciate that the treadmill shown inFIG. 1A is not intended to be limiting and that other exercise machinescan be used without departing from the concepts herein disclosed.

The chamber 102 may comprise a flexible chamber or enclosure, and may bemade of any suitable flexible material. The flexible material maycomprise a sufficiently airtight fabric or a material coated or treatedwith a material to resist or reduce air leakage. The material may alsobe slightly permeable or otherwise porous to permit some airflowtherethrough, but sufficiently airtight to allow pressure to be increaseinside the chamber. The chamber 102 may have a unibody design, or maycomprise multi-panels and/or or multiple layers. In some variations, thechamber 102 may comprise one or more flexible portions and one or moresemi-rigid or rigid portions. Rigid portions may be provided to augmentthe structural integrity of the chamber 102, and/or to control theexpansion or collapse of the chamber 102. The rigid portions may have afixed position, e.g., affixed to a fixed platform or rail, or maycomprise a rigid section, panel, or rod (or other reinforcement member)surrounded by flexible material which changes position with inflation ordeflation. In other examples, the chamber 102 may comprise a frame orother structures comprising one or more elongate members, disposedeither inside and/or outside of a flexible enclosure, or integrated intothe enclosure material(s). A rigid enclosure or a rigid portion may bemade of any suitable rigid material, e.g., wood, plastic, metal, etc.

The user seal 104 of the chamber 102 may comprise an elliptical,circular, polygonal or other shape and may be made from flexiblematerials to accommodate various shapes and/or sizes of waistline ofindividual user 101. The user seal 104 may be adjustable to accommodatepersons of different body sizes and/or shapes, or configured for aparticular range of sizes or body forms. Non-limiting examples of thevarious user seal designs include the use of zippers, elastic bands, acinchable member (e.g., drawstrings or laces), high friction materials,cohesive materials, magnets, snaps, buttons, VELCRO™, and/or adhesives,and are described in greater detail in International Patent Appl. SerialNos. PCT/US2006/038591, PCT/US2008/011807, and PCT/US2008/011832, whichwere previously referenced and incorporated by reference. In someexamples, the user seal 104 may comprise a separate pressure structureor material that may be removably attached to the chamber 102. Forexample, the user seal may comprise a waistband or belt with panels or askirt, or a pair of shorts or pants. One or more of above listedattaching mechanisms may be used to attach such separate pressureclosure to the user's body in a sufficiently airtight manner. The seal104 may be breathable and/or washable. In some embodiments, the seal 104may seal up to the user's chest, and in some variations the seal 104 mayextend from the user's waist region up to the chest.

The user seal 104 and/or chamber 102 may comprise a plurality ofopenings 105. The openings 105 may be used to alter the temperatureand/or humidity in the chamber or the torso region of the user, and/ormay be configured to control the pressure distribution about the waistor torso of the user 101. For example, openings positioned in front ofthe user's torso may prevent pressure from building up around the user'sstomach due to ballooning of the flexible waist seal under pressure. Theopenings may comprise regions of non-airtight fabrics, or by forminglarger openings in the wall of the chamber 102. The openings may have afixed configuration (e.g., fixed effective opening size) or a variableconfiguration (e.g., adjustable effective opening size or flow). Theopenings may comprise a port or support structure, which may providereinforcement of the patency and/or integrity of the opening. The portor support structure may also comprise a valve or shutter mechanism toprovide a variable opening configuration. These openings may be manuallyadjustable or automatically adjustable by a controller. In somevariations, the openings with a variable configuration may beindependently controlled.

As mentioned previously, a pressure control system 103 may be used tomanage the pressure level within the chamber 102. Various examples ofpressure control systems are described in International Patent Appl.Serial Nos. PCT/US2006/038591, PCT/US2008/011807, and PCT/US2008/011832,which were previously incorporated by reference. As illustrated in FIG.1A, the pressure control system 103 may comprise one or more pressuresensors 120, a processor 122, and a pressure source 114. The pressuresource 114 may be a pump, a blower or any type of device that mayintroduce pressurized gas into the chamber 102. In the particularexample in FIG. 1A, the pressure source 114 comprises a compressor orblower system 126, which further comprises an inlet port 124 forreceiving a gas (e.g., air), an outlet port 128 to the chamber 102. Thecompressor or blower system 126 may comprise a variable pump or fanspeed that may be adjusted to control the airflow or pressure to thechamber 102. In other examples, the pressure control system may belocated within the chamber, such that the inlet port of the system islocated about a wall of the chamber and where the outlet port of thesystem is located within the chamber.

In some variations, the DAP system 100 may further comprise a chamberventing system 116. The venting system 116 may comprise an inlet port130 to receive gas or air from the chamber 102, one or more pressureregulating valves 132, and an outlet port 134. The pressure regulatingvalve 132 and its outlet port 134 may be located outside the chamber102, while the inlet port 130 may be located in a wall of the chamber102 (or base). In other variations, the pressure regulating valve andthe inlet port may be located within the chamber while the outlet portis located in a wall of the chamber or base. The valve 132 may becontrolled by the pressure control system 103 to reduce pressures withinthe chamber 102, either in combination with the control of the pressuresource 114 (e.g., reducing the flow rate of the blower 126) and/or inlieu of control of the pressure source 114 (e.g., where the pressuresource is an unregulated pressure source). The valve 132 may also beconfigured for use as a safety mechanism to vent or de-pressurize thechamber 102, during an emergency or system failure, for example. Inother variations, the DAP system may comprise a safety valve (not shown)separate from the pressure regulating valve, where the safety valve mayact as a safety mechanism as described immediately above. In theseinstances, the separate safety valve may be configured to have a largeropening or provide a higher flow rate than the pressure regulatingvalve.

In some examples, the processor 122 may be configured to control and/orcommunicate with the pressure source 114, a chamber pressure sensor 120,the exercise system 112, a user interface system (e.g., a user controlpanel) 118, and/or a portion of the access assist device 136. Thecommunication between the processor 122 and each of above referencedcomponents of the control system 103 may be one-way or two-way. Theprocessor 122 may receive any of a variety of signals to or frompressure source 114, such as on/off status and temperature of thepressure source 114, the gas velocity/temperature at the inlet port 124and/or the outlet port 128. The processor 122 may also send or receivesignals from the control panel 118, including a desired pressure withinthe chamber 102, a desired percentage of body weight of the individualto be offset, an amount of weight to offset the user's body weight,and/or a pain level.

The processor 122 may also receive input from the pressure sensor 120corresponding to the pressure level within the chamber 102. Based on itsinput from any of above described sources, the processor 122 may send adrive signal to the pressure source 114 (or pressure regulating valve115) to increase or decrease the airflow to the chamber 102 so as toregulate the pressure within chamber 102 to the desired level. In somevariations, the desired pressure level may be a pre-set value, and inother variations may be a value received from the control panel 118 orderived from information received from the user, e.g., via the controlpanel 118, or other sensors, including weight sensors, stride frequencysensors, heart rate sensors, gait analysis feedback such as from acamera with analysis software, or ground reaction force sensors, etc.The processor 122 may send signals to change one or more parameters ofthe exercise system 112 based on the pressure reading of the chamber 102from the pressure sensor 120 and/or user instructions from the controlpanel 118. The processor 122 may send signals to control or move one ormore portions of the access assist device 136. For example, theprocessor 122 may send a control signal to hoist device 140 to raise orlower connection portion 142, or to move hoist device 140 relative toframe 138.

In some embodiments, as described generally above, the DAP system mayinclude sensors for measuring the weight or load exerted in the chamber.For example, as shown in FIG. 1A, chamber load sensors 143 may be placedinside and on the bottom of the chamber 102. While the user is in thechamber 102, the chamber load sensor 143 measures the weight of the loadsupported by the chamber 102. In other variations, there are multiplechamber load sensors 143 present. These sensors may be placed on abottom surface of the chamber 102 such as on the exercise device (e.g.treadmill) or on the base or platform 108 of the DAP system such thatthe load sensors 143 can measure the weight of the user supported by thechamber 102. In other variations, the load sensors 143 may be placedunder the exercise device such as under the belt of a treadmill so thatwhen a user is on the exercise device, the load sensor 143 measures theweight of the user applied to the device. In further variations, theload sensor 145 may be part of the user seal 104. For example, thesensor 145 may be attached to a frame supporting the user seal 104. Thesensor 145 may measure the weight of the user supported by the chamber102 while the chamber 102 is sealed.

In addition, the access assist device may have one or more load sensors141 equipped to measure the load supported by the access assist devicewhen the user is connected or attached to the assist device. As shown inFIG. 1A, the load sensor may be affixed to a portion of an overheadsuspension assist device. Depending on the location of the load sensoron the DAP system or the access assist device, any number of suitablesensors may be used. For example, a sensor designed to measurecompression may be used under the exercise device to measure the weightexerted from above the exercise device. For an overhead suspensionsystem such as the access assist device shown in FIG. 1A, the sensor maybe designed to measure tension exerted against the access assist deviceas the device supports the weight of the user from above. Other types ofload sensors include piezoelectric gauges, strain gauges, and springmechanisms. In some embodiments, the load is derived from the deflectionof a spring mechanism by way of a spring with a known spring rate, anddeflection when a force is applied.

The term load sensor as used herein is not used in any limiteddefinition but includes all sensors or devices that can measure theweight of the user. As such, although the sensors shown in FIG. 1Aappear to be attached to portions of the DAP system, in some variations,the load supported by the chamber or the access assist device may bereceived from the control panel 118 or derived from information receivedfrom the user, e.g., via the control panel 118, or other sensors such asa shock absorption sensor that measures the force of an impact exertedagainst the DAP system. Similarly, the weight of the user may be derivedfrom other aspects of the DAP system, for example, the user's weight ona treadmill may be derived from a comparison of the power needed to movea stopped belt without a user to the power needed to move a stopped beltwith the user on the treadmill.

Additionally, the processor 122 may be configured to control and/orcommunicate with any of the load sensors 141, 143, 145. Thecommunication between the processor 122 and the load sensors may beone-way or two-way. The processor 122 may receive any of a variety ofsignals to or from the load sensor such as the weight exerted on anaccess assist device or other portion of the DAP system, on/off statusof a load sensor, changes in the weight exerted, and/or direction of theweight exerted (e.g. right, left, etc.). The processor 122 may also sendor receive signals from the control panel 118, regarding the body weightof the individual. FIG. 1AA shows communication lines 151, 153, and 155between load sensors 141, 143, 145 and the processor 122 respectively.

The control panel 118 may also be used to initiate or perform one ormore calibration procedures. Various examples of calibration proceduresthat may be used are described in International Patent Appl. Serial Nos.PCT/US2006/038591 and PCT/US2008/011832, which were previouslyincorporated by reference in their entirety. Briefly, the pressurecontrol system 103 may apply a series or range of pressures (or airflowrates) to a user sealed to the DAP system 100 while measuring thecorresponding weight or ground reaction force of the user. The weight ofthe user may be measured by any number of load sensors in the DAP systemand/or access assist device, for example, load sensors 145 in the baseof the DAP system may provide the weight of user exerted in the chamber102 and load sensor 141 can provide the weight of the user supported bythe access assist device. In embodiments where the user's weight isapportioned among different load sensors, the total weight of the useris the sum of the load measured by the load sensors at each pressurepoint.

Based upon the paired values of pressure and corresponding weight, thepressure control system can generate a calibrated interrelationshipbetween pressure and the relative weight of a user, as expressed as apercentage of normal body weight or gravity. In some examples, theseries or range of pressures may be a fixed or predetermined series orrange, e.g., the weight of the user is measured for each chamberpressure from X mm Hg to Y mm Hg in increments of Z mm Hg (any unit ofpressure may be used). X may be in the range of about 0 to about 100 ormore, sometimes about 0 to about 50, and other times about 10 to about30. Y may be in the range of about 40 to about 150 or more, sometimesabout 50 to about 100, and other times about 60 to about 80. Z may be inthe range of about 1 to about 30 or more, sometimes about 5 to about 20and other times about 10 to about 15. The fixed or predetermined seriesor range may be dependent or independent of the user's weight or mass,and/or other factors such as the user's height or the elevation abovesea level. In one specific example, a user's baseline weight is measuredat atmospheric pressure and then X, Y and/or Z are determined based uponthe measured weight.

In still another example, one or more measurements of the user's staticground reaction force may be made at one or more non-atmosphericpressures and then escalated to a value Y determined during thecalibration process. In some examples, the pressure control system mayalso include a verification process whereby the chamber pressure isaltered to for a predicted relative body weight and while measuring ordisplaying the actual body weight. In some further examples, during thecalibration procedures, if one or more measured pressure or groundreaction force values falls outside a safety range or limit, theparticular measurement may be automatically repeated a certain number oftimes and/or a system error signal may be generated. The error signalmay halt the calibration procedure, and may provide instructions tothrough the control panel 118 to perform certain safety checks beforecontinuing.

In other variations, as shown in flowchart FIG. 1B, the DAP system maybe calibrated by applying pressure to the portion of the user's body inthe chamber by inflating the chamber at a predetermined pressure. Theweight of the individual is then measured (for example as the sum totalof the load sensors present in the DAP system). The measured weight fromthe load sensors may be directly communicated to the processor, whichthen can generate a weight-pressure relationship for the user. In someembodiments, the relationship between pressure and weight is generatedby interpolating the measured values and predetermined pressure valuesacross the full operating pressure range of the system. Multiplemeasured points may be desirable in the event of non-linear relationshipgenerated during the calibration process.

In some cases, the relationship generated may be between “actual” weightof the user and pressure. As used herein, actual weight refers to thetotal weight of the user measured by the load sensors. The actual weightmay be the same as the weight of the individual outside the DAP system.For example, at ambient pressure, the user's body weight is the same asthe actual weight. However, under positive pressure in the chamber, theuser's actual weight may be different and less than the normal ambientbody weight because the pressure in the chamber provides a supportiveupward force to offset a portion or substantially all of the user's bodyweight.

Similarly, the load or total load measured by the load sensors mayinclude only the user's weight or in some circumstances the user'sweight with system weight. In some cases (see FIGS. 20 and 21 describedin further detail in a later section), the load of the user is obtainedby deducting the load of the system (and access assist device ifpresent) prior to the user's use. For example, FIG. 20 shows that thebaseline weight/load measured prior to the user's use is deducted fromthe total weight of the system with the user. FIG. 21 shows that theload sensors are zeroed before the user enters the system. Depending onthe placement of the load sensors, all or a subset of the load sensorswill need to be zeroed or baseline loads measured prior the user's use.For load sensors in the base or platform of the DAP system, thosesensors may be constantly registering the weight of the system on thebase/platform. In such embodiments, the user's weight will be subsumedin the load measured when the user is standing on the chamber. To obtainthe user's weight, the baseline weight (of the system without user) willneed to be subtracted from the total weight measured by the load sensorsin the chamber with the user. As shown in FIGS. 20 and 21, this processcan be done by obtaining baseline measurements or by zeroing the loadsensors prior to use. Additionally, not every load sensor may berequired for calibration. In situations where one or more load sensorsmeasure negligible values, the load sensors can be ignored forcalibration. This can be the case where an access assist device 142provides no support during the calibration process and the user isstanding in the chamber substantially unassisted by the lift accessdevice 142. In such cases, the load sensor 141 can be ignored forcalibration. Furthermore, rather than measuring a baseline each time, abaseline load of the system may be inputted into the system for usereach time the system is calibrated or operated.

FIGS. 2A-2C, 3A, 3B, 4A, 4B, and 5 illustrate various portions of oneembodiment of a contemplated DAP system 300. This DAP system 300comprises a pressure chamber 310 with a user seal 350, an optionalexercise machine within the chamber 310 (not shown), a frame 320, aconsole 330, and an access assist device. Although DAP system 300 maycomprise an access assist device, the components of access assist deviceare not illustrated in FIGS. 2A to 2C to allow unimpeded views of theremaining portions of DAP system 300. The DAP system 300 may alsocomprise a height adjustment mechanism 334 to alter the height of a userseal 350, and a locking mechanism 333 may also be provided to maintainthe adjustment mechanism 334 at a desired position. Features andvariations of the DAP system 300 are discussed in greater detail below.

FIGS. 2A and 2B schematically illustrate the DAP system 300 with thepressure chamber 310 in an expanded state. Although the chamber 310 isshown with surfaces having generally planar configurations, in use, atleast some if not all of the surfaces may bulge outward when inflated orpressurized. The chamber 310 may be configured with a particular shapeor contour when pressurized and/or depressurized or otherwise collapsed.

Certain shapes or contours may be useful to accommodate particularmovements or motions, including moving a mobility impaired user into andout of the chamber 310. For example, for a disabled user who iswheelchair-bound, the chamber 310 may have a larger, collapsible shapeto accommodate the rolling of a wheelchair near the entrance of thechamber 310 and the sliding of the user across the collapsed chamber 310into the opening of the chamber 310 prior to inflation. The chamber 310may also be designed to accommodate the placement of an access assistdevice outside but near the chamber 310 such as a ramp abutting theopening of the chamber 310 where the user can slide into the openingdirectly from the wheelchair.

Certain shapes or contours may also be useful in controlling the shapeof the enclosure in the collapsed state to minimize loose fabric whichwould otherwise create a tripping hazard. In FIG. 2A, for example, thechamber 310 has a greater length relative to its width. The ratiobetween the length and the width of the chamber may be in the range ofabout 1.5:1 to about 5:1 or greater, in some examples about 2:1 to about4:1 and in other examples in the range of about 2.5:1 to about 3.5:1. Anelongate length may permit the use of a treadmill, and/or accommodatebody movements associated with some training regimens. For example, anelongate chamber length may provide increased space for forward legextensions and/or rearward leg kicks associated with running and otherforms of ambulation. In other variations, the chamber may have a greaterwidth than length, and the ratios of length to width may be the oppositeof the ranges described above, or a shape or footprint different from arectangle, including but not limited, to a square, circle, ellipse,teardrop, or polygon footprint, for example.

Referring to FIG. 5, the chamber 310 may also have a variable width,with one or more sections of the chamber 310 having a different widththan other sections of the chamber 310. For example, the chamber 310 maycomprise a reduced superior central width 360, as compared to thesuperior anterior width 362 and/or the superior posterior width of thechamber 310. Also, the superior anterior width and the superiorposterior width may be similar, while their ratios to the centralsuperior width are about 5:3. In other examples, the ratio may in therange of about 1:2 to about 4:1 or higher, in some examples about 1:1 toabout 3:1, and in other examples about 5:4 to about 2:1. The superiorwidth of anterior, central and/or posterior regions may also be smalleror a greater than the inferior width 366, 368,370 of the same ordifferent region. The ratio of a superior width to an inferior width maybe in the range of about 1:4 to about 4:1, sometimes about 1:2 to about1:2, and other times about 2:3 to about 1:1. The bag may be contoured toallow for volumetric efficiency in placing additional components inunused space.

Referring back to FIGS. 2A to 2C, the superior to inferior widths of theanterior and posterior regions may be about 2:3, while the ratio in thecentral region may be about 2:5. One or more sections of the chamber 310may comprise any of a variety of axial cross-sectional shapes, includingbut not limited to trapezoidal or triangular cross-sectional shapes.Other shapes include but are not limited to square, rectangular, oval,polygonal, circular, and semi-circular shapes (or other portion of acircle or other shape), and the like. Two or more sections of thechamber along the same directional axis may have the same or a differentcross-sectional shape. A chamber 310 with a reduced superior centralwidth (or other region adjacent to the user seal 350) may provideincreased space above or outside the chamber 310 to accommodate armswing during ambulation, permit closer positioning of safety handrails,and/or or use of ambulation aids (e.g., walker or cane). In otherexamples, the superior central width of the chamber, or other section ofthe chamber, may be increased relative to one or more other sectionsdescribed above, and in some specific examples, the chamber may beconfigured to facilitate resting of the aims or hands on the chamber, oreven direct gripping of the chamber with one or more handles.

The chamber of a DAP system may have a fixed or variable height alongits length and/or width, as well as a variable configuration along itssuperior surface. The vertical height of the chamber may be expressed asa percent height relative to a peak height or to a particular structure,such as the user seal. The peak height of a chamber may be locatedanywhere from the anterior region to the posterior region, as well asanywhere from left to right, and may also comprise more than one peakheight and/or include lesser peaks which are shorter than the peakheight but have downsloping regions in opposite directions from thelesser peak. The superior surface may comprise one or more sectionshaving a generally horizontal orientation and/or one or more sectionswith an angled orientation that slopes upward or downward from anteriorto posterior, left to right (or vice versa). Some configurations mayalso comprise generally vertically oriented sections (or acutelyupsloping or downsloping sections) that may separate two superiorsections of the chamber.

As depicted in FIG. 2C, the chamber 310 may comprise an anterior regionwith a height that is about 50% or less than the height of the user seal350, but in some variations, the height may be anywhere in the range ofabout 1% to about 100% of the peak height, sometimes about 5% to about80%, and other times about 20% to about 50%. A reduced height region mayprovide additional space within the chamber for internal structures,such a treadmill, while providing space above the reduced height regionfor external structures. The internal and external structures may have afixed location or a movable position.

The pressure chamber may be assembled or formed by any of a variety ofmanufacturing processes, such as shaping and heating setting theenclosure, or attaching a plurality of panels in a particularconfiguration. The chamber 310 illustrated in FIGS. 2A to 2C comprisestwo side panels 312 and a middle panel 313, but in other variations,fewer or greater number of panels may be used to form the same or adifferent chamber configuration. For example, a side panel may beintegrally formed with one or more portions of the middle panel or eventhe other side panel. As schematically illustrated in FIGS. 3A and 3B,these panels 312 and 313 may be cut or manufactured from sheet-likematerial but are then attached in non-planar configurations. The middlepanel 313 of the chamber 310 may comprise an elongate sheet of materialhaving an anterior edge 371, a posterior edge 373 and two non-linear,centrally narrowed lateral edges 375, such that the middle panel 313 hasa greater width anteriorly and posteriorly than centrally. The sidepanels 312 may have an irregular polygonal shape, comprising a generallylinear horizontal inferior edge 372, a generally linear verticalanterior edge 374, and a generally linear vertical posterior edge 376,while the superior edge comprises an generally horizontal first superioredge 378, a generally vertical second superior edge 380, a generallyupsloping third superior edge 382, a generally horizontal fourthsuperior edge 384, and a generally downsloping fifth superior edge 386.The transition from one edge to the adjacent may be abrupt or gradual,and may be angled or curved. Although the side panels 312 and thelateral edges 375 of the middle panel 313 may be generally symmetricalor mirror images, while in other variations the side panels and/or thelateral edges of the middle panel may have asymmetric configurations.The characterization of some or all the edges of the shape into generalorthogonal orientations (e.g., anterior/posterior/superior/inferior) isnot required may vary depending upon the reference point used. Thus, inthe example above, the second superior edge 380 may also becharacterized as an anterior edge, while edge 378 may be characterizedas either an anterior or superior edge. In other variations, one or moreof the edges of the panel may be generally curved or non-linear, and maybe generally upsloping, downsloping, vertical, or horizontal, and maycomprise multiple segments. The panels may have a shape the promotesfolding such as a stiffer outer section and more flexible inner sectionas shown in FIGS. 6A and 6B, which resembles a butterfly or hourglassshape, but could also be any of a variety of other suitable shapes witha reduced central dimension.

The edges or edge regions of the two side panels 312 may be attached tothe lateral edges 375 (or lateral edge regions) of the middle panel 313,e.g., the anterior edge 374 of the side panel 312 is attached to firstedge 374′ of the middle panel 313, etc. The various edges of the middlepanel 313 may be characterized (from anterior to posterior, or otherreference point) as parallel edges 378′ and 384′, tapered edges 374′,380′ and 382′ or flared edges 388′. The edge or edge regions may beattached and/or sealed by any of a variety of mechanisms, including butnot limited to stitching, gluing, heat melding and combinations thereof.The chamber may also be formed from a single panel which may be foldedor configured and attached to itself (e.g., edge-to-edge,edge-to-surface or surface-to-surface) to form a portion or all of thechamber. FIGS. 4A and 4B are orthogonal frontal view superior views,respectively of the chamber 310 in an assembled and expanded state, andschematically depicting the contours of the chamber 310. FIG. 4Aschematically illustrates the wider base and narrower superior surfaceof the chamber 310, which may provide an offset or a gap 401 betweenside panel 312 of the chamber 310, as depicted in FIG. 4B. In someexamples, a superiorly tapered chamber may reduce the amount of fabricor material used and/or may reduce the degree of bulge when the chamberis pressurized.

In some embodiments, the chamber or panels of the chamber may beconfigured with pre-determined fold lines or folding regions that mayfacilitate folding or deflation of the chamber along the fold lines orregions to assume a pre-determined shape. For example, the chamber mayhave an accordion or bellows-like configuration that biases the chamberto collapse to a pre-determined configuration along folds with analternating inward and outward orientation. The pre-determined foldlines include but are not limited to the interface between flexible andrigid regions of the chamber, creases along a panel, or panel regionsbetween generally angled edges of adjacent panels, for example. In somevariations, fold lines may be creases or pleats provided by heat settingor mechanical compression. In other variations, fold lines may be madeby a scoring or otherwise providing lines or regions with reducedthicknesses. Fold lines may also be provided along a thickened region,rigid region, ridge or other type of protrusion. Other fold lines may beprovided by stitching or adhering strips of the same or different panelmaterial to the chamber, and in other variations, stitching orapplication of curable or hardenable material (e.g., adhesive) alone maysuffice to control folding. In still other variations, fold lines may beprovided by attaching or embedding one or more elongate members (e.g., arail or a tread made by NITINOL™) along the chamber. An elongate membermay have any of a variety of characteristics, and may be linear ornon-linear, malleable, elastic, rigid, semi-rigid or flexible, forexample. The chamber or panels may comprise pre-formed grooves orrecesses to facilitate insertion and/or removal of the elongate members,and in some variations, may permit reconfiguration chamber for differenttypes of uses or users. In some embodiments, the fold-lines may compriseone or more mechanical hinge mechanisms between two panels (e.g., livinghinges) that are either attached to the surface of the chamber orinserted into chamber pockets. Each fold line of a chamber may have thesame or a different type of folding mechanism. Collapse of the chamberin a pre-determined fashion may also be affected by elastic tensionelements or bands attached to the chamber.

As illustrated in FIGS. 4A and 4B, the middle panel 313 of the chamber310 may comprise one or more fold lines 391, 393 and 395 which may helpthe chamber deflate or collapse into a pre-determined shape orconfiguration. In some examples, the pre-determined shape may facilitateentry and/or separation between the user and the system by reducingprotruding folds or surface irregularities that may trip or otherwisehinder the user. The fold line 393 may be configured (e.g., with aninternal angle greater than about 180 degrees by virtue of the sidepanel shape) to fold the adjacent external surfaces of the middle panel313 against each other. This configuration in turn, may facilitate thenearest fold lines 391 and 395 to fold so that their adjacent internalsurfaces fold against each other. The pre-determined fold lines 391, 393and 395 in the anterior region of the chamber may result in acorresponding flattening of the posterior chamber.

As illustrated in FIG. 5, the front and back edges 373 and 375 of themiddle panel 313 and the inferior edge 372 of the side panels areattached to the system platform or base 321 rather than a flexible panelor material, but in other variations, an inferior panel may be provided.The side panels 312 may be made from the same or different material asthe middle panel 313 of the chamber 310, and in some variations, theside panels may also comprise different materials. In some variations,the stretch or flexible properties (or any other material properties)may be anisotropic. For example, the middle panel 313 of the chamber 310may be made from a less stretchable material in order to limit thechamber's expansion in transverse direction (i.e., along X axis in FIG.5). The side panels 312 may be made from a more stretchable material,which may or may not redistribute the tension acting on the lessstretchable portions of the chamber 310. The side panels 312 maycomprise a relatively more flexible material, which may facilitate apre-determined folding pattern of the middle panel 313 when deflated orcollapsed. The chamber 310 may be made of any suitable flexiblematerial, e.g., a fabric (woven or nonwoven), a polymeric sheet (e.g.,polyurethane, polypropylene, polyvinylchloride, Nylon®, Mylar®, etc.),leather (natural or synthetic), and the like. The materials may beopaque, translucent or transparent. In some embodiments, the outersurface of the middle panel 313 may be coated with anti-slip materialsor coatings, and/or may comprise ridges or other surface texturing toresist slipping when a user steps onto the deflated chamber 310.

FIGS. 6A to 6C depict one example of a pressure chamber 610 comprisingmultiple panels with different material characteristics. Here, the sidepanels 612 and the middle panel 613 further comprise generally airtighttransparent windows 630, 632, 634, 636 and 638. The user seal 650 mayalso comprise one or transparent or translucent regions. In someexamples, transparent materials may permit a healthcare provider orother observer to view the movement of the user (e.g., gait analysis),or to improve the safety of the system by permitting viewing of thechamber contents, in the expanded and/or collapsed states. The windowsmay also permit the user to view his or her lower limbs, which maypromote gait stability and/or balance. The side windows 630 of the sidepanels 612 may also comprise non-linear, concave edges 640 and 642anteriorly and posteriorly. In some examples, the concave edges 640 and642 may facilitate folding of the side panels 612 along fold line 647.As shown in FIG. 6C, the outfolding, rather than infolding, of the sidewindows 630 may also be facilitated by the bulging side windows 630 inthe pre-collapsed/pressurized state. In some examples, by promoting theoutfolding of the side windows 630 in the collapsed configuration, theremay be less chamber material adjacent to the user seal 650 which a usermay trip or step on when entering the system. This may permit thesuperior posterior section 644 of the lie in a flatter orientation andto span the area from the posterior edge 677 of the middle panel 613 tothe user seal 650. In some variations, a rod or other elongate element648 (as shown in FIG. 6B) may be attached horizontally between theposterior windows 636 and 638 to facilitate the folding along fold line649. The elongate element 548 may be attached to the interior orexterior surface, and/or partially or completely embedded within thepanel material itself. In some examples, the rod or elongate element maycomprise a significant weight such that upon depressurization of thechamber, the weight of the rod and its location along a sloped surfaceof the chamber may facilitate the inward folding of the chamber. Anon-slip layer 646 of material may be provided on the superior posteriorsection 644, which may promote safe ingress and egress from the chamber610. A non-slip layer may also be reinforced or made of substantiallystiff material to assist in contouring of the chamber to aid in foldingand prevent wrinkling where deflated, thereby reducing the trip hazard.In other examples, the concave or inwardly angled edges may be locatedmore inferiorly or more superiorly, and may also be located along otheredges of the window (or panel) or multiple sites may be found along oneedge. In still other variations, one or more edge may comprise a convexor outwardly angled edge, which may facilitate folding in the oppositedirection.

Although various shapes, dimensions, contours, materials, etc. have beendescribed for the chamber, it can be appreciated that any number ofcombinations of these features may be suitable for a target user ortreatment. For example, some embodiments provide for DAP systems withoutan exercise device. For some users the mobility impairment may be sosevere that exercising on a device is nearly impossible or evendangerous. For example, a paraplegic with lower body paralysis cannotwalk or run on a treadmill per se. Rather for these users, beingpositioned upright in a pressure chamber is sufficient activity toimprove movement, circulation, and overall health. In other cases, anindividual may conduct activities that do not require a device such assquatting, lunging, walking in place, jumping, sitting on a balance ballinside the chamber. Accordingly, the DAP systems described can be usedwith or without an exercise device. For example, the DAP systems shownin FIGS. 2A-2C and FIGS. 7A-7E include a platform or base for the userto stand or move upon in the chamber. An exercise device can beoptionally added to bottom of the chamber if needed. In such cases, thechamber may be designed to accommodate these activities. A compliantmaterial that allows vertical flexibility so that a user sealed in thechamber can jump or squat can be used. Moreover, the shape of thechamber can be configured to give the user more flexibility. As anexample, the middle panel 613 and side panels 612 of the chamber asshown in FIGS. 6A-6C merge to create a neck portion 2600 at the top ofthe chamber. In some embodiments, the neck portion is extended to allowgreater compliance at the top of the chamber. This allows a user tomaneuver vertically for squatting, lunging, etc. In some variations, thechamber provides about 10-20 inches of compliance. Moreover, theplatform or base of the chamber 321 can include load sensors 1004 (seeFIG. 2C) to measure the weight of the user exerted against the platform.

A DAP system may comprise an attachment mechanism to couple and/or seala pressure chamber to the base of the system in a sufficiently airtightmanner to maintain pressurization within the chamber, such as thosedescribed in International Patent Appl. Serial No. PCT/US2010/034518,which was previously incorporated by reference in its entirety.

In some embodiments, the DAP system also includes a frame assembly withvarious structures to support and/or stabilize other structures of theDAP system. For example, the frame assembly may comprise a platform orbase to attach the inflation chamber, as well as bars, braces or railsthat limit the shape the inflation chamber. The frame assembly may alsobe used to stabilize the height adjustment mechanism, using variousframe structures to dampen vibrations or stabilize other stressesgenerated by or acting on the DAP system or the user during use. In theexample depicted in FIGS. 2A to 2C, the DAP system 300 comprises a frameassembly 320 with a base 321, side hand-rails 322, a front horizontalbar 323 and front vertical bars 324. Some portions of the frame assembly330 may also maintain or limit the chamber to a predetermined shape. Forexample, when chamber 310 is inflated, the expansion of the chamber 310at the front end of the system 300 is limited by side bars 325, L-shapebars 326, and the front bar 327 of the front brace 324. The lateralexpansion of the chamber 310 may be limited by the rear hand-rails 322.The rear hand-rails 322 may provide support to a user during exerciseand/or in the event of pressure change within the chamber 310, which maycause the user to lose body balance temporarily. In some embodiments, apressure source may be placed upon or mounted to the two L-shape bars326. In one example, the pressure source may be a blower. The pressuresource may be placed at other locations as well. For example, it may beplaced on the ground next to the DAPS to reduce vibration that may becaused by the pressure source.

The frame assembly 320 may be assembled together by any suitable methodsknown to the ordinary skilled in the art. Non-limiting examples includebrackets, bolts, screws, or rivets. In some embodiments, in addition toor in lieu of the components described above, the frame assembly 320 maycomprise other components or parts. For examples, additional bars orbraces may be used to stabilize the system 300 while the user is inmotion.

In other examples, one or more other structures may be attached to theframe assembly to facilitate certain types of exercise or training. Forexample, the adjustment mechanism may further comprise a walker or canemechanism to simulate, facilitate or coordinate upper body lifting andplanting motions associated with walker or cane use. In some examples,the walker or cane mechanism may incorporate sensors which may besynchronized to the treadmill or other exercise machine used with theDAP system. In still other examples, one or more panels of the chambermay be sealably opened to permit access to the enclosed portions of thebody. Also, in further examples, the chamber and/or the frame assembly,or may include harnesses or straps to provide non-pneumatic bodysupport.

As noted above, the expansion of the chamber 310 in the embodimentdepicted in FIGS. 2A to 2C may be limited by several bars, rails and/orbraces of the frame assembly 320 of the DAP system 300. In this specificembodiment, the two parallel height adjustment mechanisms 334 may alsofacilitate shaping the inflated chamber by limiting its lateralexpansion. As illustrated in FIG. 2A, the vertical expansion of aninflated chamber 310 around a user seal 350 may be limited by a consoleframe 331 of the movable assembly 330. When a user is positioned in theinflated chamber 310 while using the system 300, the seal frame 341 ofthe movable assembly 330 may be disposed just at or above the user'swaistline. As best illustrated in FIG. 2B, the seal frame 341 of themovable assembly 330 may be of approximately the same width as the topsection 313 of the chamber 310, but may be slightly wider than the userseal 350. As a result, when chamber 310 is inflated, the disposition ofthe console frame may allow the user seal 350 to rise but depressbulging chamber material around the seal 350. This design may prevent orreduce the risk that the bulging chamber material around the user seal350 from interfering with the user's upper body motion and allow theuser to swing arms freely and comfortably. As will be discussed infurther detail below, the top section 313 of the chamber 310 may beattached to the a portion of console frame 331, thereby allowing theheight of user seal 350 to be adjusted with the height of movableassembly 330.

In addition to the structures that have been described here, additionalstructures may be used to limit the expansion of the chamber 310 inorder to contour the chamber to a specific configuration. For example,X-shape cross-bars may be added between the height adjustment mechanism334 and the rear hand-rails 322 to flatten the bulging chamber materialon the sides of the base. In some embodiments, the chamber 310 maycomprise one or more rigid portions or other types of integratedsupporting structures that may facilitate maintaining the inflatedchamber in a particular configuration or shape.

A DAP system may be configured to be height-adjustable, such that theuser-seal/opening of a chamber may be adjusted to help facilitate useraccess to a chamber. For example, in the DAP system 300 shown in FIGS.2A-2C, seal frame 341 may be configured to attach to chamber 310, andmay be height adjustable. Height adjustability may facilitate use of theuser seal 350 at a particular body level or body region (including useof the system by shorter patients), may also provide a limit or stopstructure to resist vertical displacement of the chamber, and may alsoallow the user seal 350 to be temporarily lowered such that a user maystep into or otherwise enter the user seal. Various examples of heightadjustment mechanisms for the seal frame are described in InternationalPatent Application Serial Nos. PCT/US2008/011832 and PCT/US2010/034518,which were previously incorporated by reference in their entirety, andthe height adjustment mechanisms may be attached to the chamber in anysuitable manner.

A DAP system may also comprise a locking mechanism, which may beconfigured to adjust and/or lock the position of the height adjustmentmechanism. In some embodiments, the locking mechanism further comprisesa control interface accessible to the user while using the system. Thecontrol interface may comprise an actuator (e.g., a button, a lever, aknob or a switch, etc.). In other embodiments, the control interface maybe integrated into the control panel where the user may control andadjust other parameters (e.g., pressure level inside the chamber,parameters of the exercise machine, etc.) of the system. Variousexamples of locking mechanisms are described in International PatentApplication Serial No. PCT/US2010/034518, which was previouslyincorporated by reference in its entirety.

The DAP system may be height adjusted manually or automatically. Forexample, in some embodiments, the user seal 350 and the seal frame 341are equipped to be raised and lowered manually by the user.Alternatively, the DAP system may have a motorized height adjustmentmechanism, such as a motorized lift, that allows the user, especially amobility impaired user, to enter the seal 350 area and have the seal 350raised to engage the user's body. This is advantageous where a disableduser cannot raise or lower the seal to the proper height independentlywithout assistance. Moreover, the power required to operate themotorized lift can also provide the user's weight to the processor. Forexample, the motorized lift may be operated by the control panel orprocessor where once the lift command is given the lift begins liftingthe user and outputting a load value signal to the processor, which canbe used to calibrate the DAP system.

As discussed above, the DAP system 300 can be configured to have one ormore load sensors to measure the weight of the user exerted on differentareas of the system. For example, as shown in FIG. 2A, the frameassembly 320 can include handrails 322 for a user to hold or lean ontofor support while entering, exiting, or using the DAP system. Thehandrails 322 may also include load sensors 1000 such that the weight ofthe user exerted on the handrails 322 is measured and transmitted to thesystem processor. In another example, the load sensors 1000 may beplaced at any point along the handrail 322 such as the midway point ortoward the front of the DAP system. As can be appreciated, any number ofpositions may be suitable depending on the mobility and comfort of theuser. Moreover, in some embodiments, the frame assembly 320 may includea slideable track system where the load sensors 1000 may be removed orrepositioned along the track (such as on the handrail 322) such that theload sensors 1000 can be adjusted and personalized for each user.Additionally, the load sensors can be built into the DAP systems oradded on to an existing system.

In some examples, the load sensors may be placed on attachablecomponents such as adhesive load sensor pads or snap-on members wherethe load sensors can be attached to various locations on the frameassembly 320 depending on the needs of the user. For example, dependingon the motor or mobility impairment, the user may need to lean in aspecific direction for support while positioned in the chamber. For auser leaning forward, the load sensors can advantageously be placedtoward the front of the DAP system. Moreover, for a subsequent user whomay lean toward the sides, the load sensors can be moved to a sidelocation from the front location. In other embodiments, the load sensorsmay be affixed as adhesive pads to the DAP system at suitable locationsto engage the user and measure the user's weight.

In further variations, load sensors may be placed on multiple locationson the system and access assist device. For example, a disabled user maybe first lifted and maneuvered by an access assist device having a loadsensor into the seal 350. Once inside the seal 350, the user may need tolean against the seal frame 341 or the frame assembly 320 for support.The DAP system may include load sensors 1002 on the user seal frame 341and/or frame assembly 320. The load sensors 1002 can be placed anywherealong the user seal frame 341 depending on the needs of the user.Furthermore, although shown as load sensors on the handrail 322 or theseal frame 341, load sensors can be placed anywhere on the DAP system toaccommodate the limits of a mobility impaired user. Moreover, the loadsensors 1004 can be in the base or platform 321 in addition to anywhereelse on the DAP system where the user can engage the system and exert aweight force against the system. Furthermore, load sensors can be placedon exercise devices or under exercise devices. In some embodiments, theload sensors are placed under a treadmill belt. In other embodiments,the load sensors may be placed on or near a user connection such as aharness or wearable support so that when a user's weight is supported bythe harness or wearable support, the weight is measured by the loadsensor.

Because mobility impaired users may have difficulty staying still,having multiple load sensors at different locations on the system canaccommodate a user who needs to shift positions during use of thesystem. As such, load sensors can be placed in any area around the spanof a user such that a user can apply weight to the area. In somevariations, this is area around the arm span of a user to allow the userto grasp, lean, push, etc. against an area for support. In othervariations, this is the space around a user's body that includes wherethe user can apply force by any means such as pushing, kicking,pressing, pulling, etc.

Furthermore, the type of load sensor may be selected depending on theanticipated load measured by a load sensor. For example, a load sensorplaced under a treadmill belt may measure a much lower range of loadsthan one placed under the treadmill. Varying degrees of resolution andrange may be selected for load sensors depending on the placement of thesensors and anticipated load measured.

Additionally, as discussed above, the load sensors can be configured toelectronically communicate with a system processor or control system toprovide load values to the processor for calibration or operation of theDAP system. The load sensors may communicate with the processor via awired electrical connection (e.g. Ethernet or electrical wiring) orwirelessly. Wireless communication methods include communicating viaWiFi, Bluetooth, or Ant+. In some embodiments, suitable load sensorsinclude load cells from Sentran, Futek, and LCM Systems.

As shown in FIG. 1A, the DAP system 100 may further comprise an accessassist device 136 for facilitating user access to the chamber 104. Forexample, for a user requiring a high level of assistance such as abedridden patient (e.g. quadriplegic) or wheelchair-bound patient (e.g.paraplegic), an access assist device may comprise a device that can beara portion or all of the user's body weight while maneuvering the user tothe chamber of the DAP system. Such devices include a lift assist devicesuch as an overhead suspension (with or without a harness) system thatattaches or connects to the user. In some embodiments, an access assistdevice 136 may comprise an access frame 138 attached to or otherwisepositioned in a fixed relationship to chamber 102. Access assist device136 may further comprise a hoist device 140, with a patient connectionportion 142 for engaging a patient. Hoist device 140 may be moveablealong at least a portion of lift access frame 138, which may allow thehoist device 140 to move a user 101 relative to chamber 102, as will bedescribed in more detail below. Additionally, patient connection portion142 (with harness 147) may be vertically moved relative to the rest ofhoist device 140 to raise or lower the user 101 relative to chamber 102.

FIGS. 7A-7E illustrate a variation of a DAP system 700 with an accessassist device 712 for lifting and moving a user/patient. Specifically,FIG. 7A shows a perspective view of DAP system 700, comprising pressurechamber 702 with a user seal 704, console 706, chamber frame 708,height-adjustable seal frame 710, and access assist device 712. As shownthere, access assist device 712 generally comprises a lift access frame714 and hoist device 716. In some embodiments, as shown in FIGS. 7Athrough 7E, the lift access frame 714 may be specifically configured tomate with, attach to, or otherwise be fixed relative to the rest of theDAP system 700.

The access assist device 712 of the DAP system may be used to assist auser in obtaining access to the user seal 704 of the pressure chamberwhen it is dangerous or difficult for a user to otherwise obtain access.For example, in variations where the DAP system contains aheight-adjustable user seal 704, the user seal 704 may be lowered toallow a user to step into the chamber 702. However, if a user haslimited mobility (e.g., by virtue of injury, illness, or othercondition), he or she may not be able to step into the pressure chamber702 without assistance. The access assist device 712 may be used to movethe user relative to the user seal 704 to assist the user in enteringthe pressure chamber 702.

Generally, in some embodiments, the lift access frame 714 can be affixedor otherwise attached to the DAP system 712, such that the hoist device716 may be moveably positioned relative to a pressure chamber 702 of theDAP system 700. The lift access frame 714 may be permanently orreversibly attached to one or more portions of the DAP system 700. Forexample, in variations where the pressure chamber 702 is attached to abase or platform FIG., the lift access frame 714 may also be attached tothat base/platform 711. In some variations, the lift access frame 714may be welded or otherwise fused to the base/platform 711. In othervariations, the lift access frame 714 may be mechanically joined to thebase/platform 711 via one or more bolts, clamps, screws, othermechanical connectors, or combinations thereof. In other variations, thelift access frame 714 may be configured to magnetically attract to andaffix to the base/platform. In still other variations, the lift accessframe 714 may be configured to be friction fit with the base/platform711. In yet other variations, the frame may contain one or more bars,struts, or other structures that project at least partially into orthrough one or more lumens, channels, or slots in the base/platform 711.Additionally or alternatively, the base/platform 711 or other portion ofthe DAP system may sit or otherwise rest upon one or more portions ofthe lift access frame 714 such that the weight of DAP system 700 mayhelp hold the frame in place.

The lift access frame may comprise any suitable configuration of supportstruts, bars, or the like. For example, in the variation of lift accessframe 714 shown in FIGS. 7A-7E, lift access frame 714 may comprise aplurality of vertical struts 718, base struts 720, and top strut 722.While shown in FIGS. 7A-7E as having four vertical struts 718, liftaccess frame 714 may comprise any suitable number of vertical struts(e.g., two, three, four, or five or more). Additionally, some or all ofvertical struts 718 need not be vertically oriented, and instead mayextend upward at an angle. As mentioned above, lift access frame 714 maybe configured to be adjustable. For example, each of the vertical struts718 may be configured such that they have variable length (e.g., eachvertical strut 718 may comprise a telescoping portion) to allowadjustment of the height of top strut 722.

Lift access frame 714 may additionally include a track system comprisingone or more tracks along which a hoist device 716 may move. In somevariations, one or more tracks of a track system may be formedseparately from the lift access frame 714, and attached thereto. Forexample, in the variation of lift access frame 714 shown in FIGS. 7A-7E,track 724 is attached to top strut 722. In other variations, one or moretracts may be integrally formed in one or more struts of the lift accessframe. While shown in FIGS. 7A-7E as having a single track that allowsfor movement in one dimension, it should be appreciated that the tracksystem may comprise multiple tracks that allow the hoist device to movein two dimensions. For example, in some directions, first and secondtracks may be attached to the lift access frame 714, and a third trackmay be slidably connected to the first and second tracks. A hoist device716 may be slidably connected to the third track, such that the hoistdevice 716 may move along the third track in a first dimension. Thethird track may slide relative to the first and second tracks to movethe hoist device is a second dimension.

In variations where the connection between lift access frame and the DAPsystem 700 is releasable, the lift access frame 714 may be configured tobe moveable relative to the DAP system (e.g., the DAP system maycomprise one or more wheels that may allow the lift access frame to bemoved). In these variations, the lift access frame 714 may be disengagedfrom the rest of the DAP system and may be moved away from the DAPsystem. This may provide utility in replacing an access assist devicewith a new or different access assist device.

Additionally, the lift access frame 714 may be configured to beadjustable. In some variations, the height of lift access frame may bevariable. This may allow the height of the lift access frame to beraised in instances where a taller patient is being transported, or maybe lowered to allow the DAP system to be moved through a doorway orother height-restricted space. Similarly, one or more portions of thelift access frame may be configured to be collapsible to allow forlower-profile transportation and/or storage of the DAP system.

In other variations, the access assist device may also include aninterlocking mechanism to ensure that the user is properly and safelymoved in and out of the chamber 702. For example, the lift access frame714 may contain one or more interlock checkpoints 705 a-c designed tocommunicate with a processor in the DAP system. When the hoist devicetravels over a checkpoint 705 b, for example, a processor controllingthe DAP system 700 (not shown) may also control the operation of theaccess assist device. The processor can check whether the pressurechamber 702 is ready to receive the user when the hoist device 716engages the checkpoint 705. This prevents the unwanted situation wherethe user may be lowered or dropped into the user seal 704 or chamber 702when the user seal is not open for receiving the user or the chamber isblocked. The checkpoints 705 may contain sensors that output a signal tothe processor when the hoist device engages a checkpoint. The processorthen checks on the status of the DAP system, in particular the user seal704 and the chamber 702. If conditions are acceptable, the processor cansend a command for the hoist device to continue moving. If conditionsare not acceptable, the hoist device 716 will not receive a “go” commandand the hoist device 716 will stop movement.

Similarly, the interlock checkpoints 705 can also act in the reverse toensure that a user is safely removed from the DAP system 700. When thehoist device 716 carrying a user out of the chamber 702 travels alongthe track 724 over an interlock checkpoint 705 b, the checkpoint outputsa signal to the processor. The processor may check the status of thesystem 700 such as whether the pressure chamber 702 has been readied foruser exit. In some embodiments the pressure chamber 702 is made from aninflatable, collapsible material. In such cases, exiting the DAP systemsafely may require that the pressure chamber 702 is substantiallydeflated and lowered below the user's torso. The interlock checkpoints705 can be designed to ensure that the user is not dragged against araised and inflated chamber while attached to a moving hoist device 716.Similarly, the processor may also check if the pressure in the chamberis at a safe level for user extraction. At a high positive pressure,attempting to remove the user may result in breaking the seal around theseal interface and allowing the upward force of the pressure toinadvertently push the user out of the chamber. Accordingly, theprocessor may check if the pressure source is off, for example, whetheran air/gas blower is off.

FIG. 14 provides a flowchart showing one embodiment of the interlockingmechanism where the processor operates the interlocking mechanism. At2200, the lift access device such as the one shown in FIGS. 7A-7E beginsmoving the user toward the chamber. Once the device moves over aninterlock checkpoint, 2202, the processor performs a check of thechamber configuration. If the chamber is configured to receive the userthen the lift access device continues toward the chamber and positionsthe user in the chamber 2204. The user is then sealed in the chamber2206. If the chamber is not configured for the user, the interlockengages and prevents movement of the lift access device 2208.

In some embodiments, the hoist device 716 is generally configured toengage a user, lift the user into the air, and to move the user relativeto the lift access frame 714 and relative to the DAP system chamber 702.For example, in the variation of DAP system 700 shown in FIGS. 7A-7E,hoist device 716 comprises a lift housing 726 and a patient connectionportion 728. A portion of lift housing 726 may engage track 724, suchthat hoist device 716 may be moveable along track 724. Hoist device 716may be moveable along track 724 in any suitable manner. In somevariations, one or more portions of the access assist device 712 (e.g.,hoist device 716) may comprise one or more motors for moving the hoistdevice 716 along track 724. In these devices, a processor or othercontrol system may control the motor to move hoist device 716 alongtrack 724. In other variations, the hoist device 716 may be manuallymovable along frame. For example, hoist device 716 may comprise areleasable locking mechanism (not shown) that may hold the hoist device716 in place relative to the track 724. The locking mechanism may betemporarily disengaged, at which point the hoist device 716 may be moved(e.g., by a user, physician, trainer or other party) along track 724.

Additionally, patient connection portion 728 may be vertically moveablerelative to lift housing 726. While shown in FIGS. 7A-7E as being ahorizontal bar 730, patient connection portion 728 may be any suitablestructure (e.g., a hook, carabiner, etc.). Generally, patient connectionportion 728 may temporarily engage a user to lift that user into theair. The patient connection portion may lift a user in any suitablemanner. In some variations, the patient connection portion 728 may beattached to a sling or seat (not shown). In these variations, a user maysit in the sling or seat (or the sling or seat may be placed underneaththe user), and the sling or seat may be lifted into the air via thehoist device. Once the user has been lowered at or near the user seal ofthe pressure chamber (as described in more detail below), he or she maystand from or may otherwise be aided from the sling or seat to astanding position in the pressure chamber.

In other variations, the horizontal bar 730 can be a handlebar for theuser to hold onto while being lifted or otherwise moved relative to thechamber 702. The bar 730 may be equipped with hand rests or handlestraps (not shown) to help a user hold onto the bar 730.

In other variations, the patient connection portion 728 may be attachedto, or may otherwise comprise one or more arm straps (not shown). Inthese variations, a user may place his or her arms through the straps,and the aim straps may lift the patient by the aims and/or shoulderswhen the patient connection portion 728 is raised. When a user islowered into the user seal 704 of a pressure chamber 702, the user maypull their arms from the arm straps.

In still other variations, the patient connection portion 728 may attachto one or more portions of the user's clothing. For example, in somevariations a user may wear a harness (e.g., a waist harness or ashoulder harness), and the patient connection portion 728 may beconnected to the harness. The patient connection portion 728 may beraised to lift the user into the air via harness, and may move the userover and/or through the user seal. Once in place, the patient connectionportion 728 may be disengaged from the harness, or the harness may bedisengaged from the user. In variations where the user seal may comprisea separate pressure structure or material that may be removably attachedto the chamber and is wearable by a user (e.g., a waistband or belt withpanels or a skirt, or a pair of shorts or pants, as described above),the separate portion of the user seal may be worn by the user andattached to the patient connection portion 728, such that the hoistdevice may lift the user via the user seal.

When engaging a user, patient connection portion 728 may be raised orlowered relative to the rest of hoist device 716 (e.g., lift housing726) to raise or lower the user. Patient connection portion 728 may beraised and lowered in any suitable manner. In some variations, the hoistdevice 716 comprises a motor (not shown) for raising or lowering thepatient. In these variations, the DAP system may comprise one or moreprocessors or other control devices for controlling the height of thepatient connection portion 728. In other variations, one or more pulleysystems may be utilized to raise or lower the patient.

FIGS. 7B-7E illustrate one access method by which access assist device712 may facilitate user access to chamber 702. It should be appreciatedthat although shown in FIGS. 7B-7E as being in a raised position, aheight-adjustable seal frame 710 of the DAP system may be lowered beforeusing access assist device 712. To use access assist device 712, hoistdevice 716 may be moved along track 724 away from chamber 702 to a firstposition, as shown in FIG. 7B. Once in the first position, the hoistdevice 716 may be locked in place, and patient connection portion 728may be lowered, as shown in FIG. 7C. Once lowered, the patientconnection portion 728 may temporarily engage a user (not shown), asdescribed in more detail above. The patient connection portion 728 maybe raised, thereby lifting the user into the air. The first position ofthe hoist device 716 may also engage an interlock checkpoint 705 a whereas described above, the control system or processor of the DAP systemchecks on the status of the DAP system's readiness for the user. Forexample, the processor may check on whether the height-adjustable sealframe 710 has been lowered to accept a user from the assist accessdevice. In some embodiments, the processor may do this check prior tothe user attaching to the hoist device or after the user is connectedbut prior to the movement of the hoist device. As can be appreciated,any number of variations on the timing and/or location of an interlockcheckpoint can be arranged as needed in the DAP system.

Once the user is connected to the hoist device 716, the hoist device 716may then be moved to a second position to place the user above the userseal (not shown) of chamber 702, as shown FIG. 7D. The patientconnection portion 728 may then be lowered to place the user at leastpartially inside of chamber 702, as shown in FIG. 7E. Prior to loweringthe user into the chamber 702 or seal, the hoist device may engage withadditional interlock checkpoints 705 a-c.

Once in place, the user may initiate a training, exercise, orrehabilitation session. In some variations, this may comprise raisingthe user seal of the chamber to a comfortable height using seal frame710 or another mechanism. Additionally or alternatively, the patientconnection portion 728 may be disengaged from the user prior toinitiating the training, exercise, or rehabilitation session, and may bemoved to another position (e.g., first position) during the session.Following the session, the steps described above may be reversed toremove the user from the chamber 702.

It should be appreciated that one or more of the steps described abovemay be performed automatically. For example, in some variations, anoperator may press a first button or other actuation mechanism toinitiate the access method. A processor or other device may beconfigured to automatically move hoist device 716 to the first position,lock the hoist device 716 in place, and lower the patient connectionportion 728. Once a user has engaged the patient connection portion 708,another button may be pressed, and the device may be configured toautomatically raise the patient connection portion 728 and the user,move the hoist device to the second position, and/or lower the patientinto the pressure chamber. The processor (or other device) may alsooptionally check the conditions of the DAP System at interlockcheckpoint(s) at any time during the process of lifting and moving thepatient/user in and out of the chamber 702. Additionally oralternatively, one or more steps may be manually controlled. Forexample, it may be desirable to manually control the lowering of patientconnection portion 728, such that the patient connection portion 728 maybe lowered to different heights depending on the height or positioningof a user. In these instances, one or more buttons or other controldevices may be used to control the positioning of the hoist device 716,and the height of the patient connection portion 728.

Although shown as an overhead lifter 712 in FIGS. 7A-7E, the accessassist device for helping a user/patient enter and exit the DAP systemcan be a variety of any number of devices for carrying and moving auser's body. For example, the DAP system may include a motorized seatlift 900 to maneuver a user vertically. In those variations, the DAPsystem may use the power required to operate the lift to derive theweight of the user. FIG. 16A shows one embodiment of the DAP system 300with a motorized lift 900 for adjusting the height of the seal frame341. In this embodiment, the user is generally placed into the sealinterface 350 while the chamber 302 is deflated and collapsed. The sealframe 341 is lowered and the user is positioned in the seal interface350 either unassisted or with help from an access assist device. Onceinside the seal interface 350, the user may be secured to the sealinterface 350 by way of a support connection such as a harness or awearable connector 907 that engages with the seal interface to maintainthe seal between the chamber and the environment outside the chamber302. Dotted line 999 shows the outline of the user's leg in theconnector 907. The seal frame 341 is then vertically lifted with theuser connected in the seal interface 350. As shown in FIG. 16A, the DAPsystem 300 includes a motorized lift system 900 with a lead nut 903,lead screw 904, and motor 905 to automatically lift the seal frame 341to a desired height. The motorized lift system 900 may include a loadsensor 902 such as a load cell configured to measure the load lifted.The load sensor may output a load signal to a processor with the loadmeasurements. In some embodiments, the processor is configured tosubtract the load lifted when the seal frame 341 without user isvertically moved from the total load lifted with the user engaged in theseal frame 341. In other embodiments, the DAP system 300 may include anexercise device 906 such as a treadmill. In some embodiments, the usermay be weighed in the motorized lift 900 by lifting the user such thatthe user's lower extremities are substantially in a standing position.This may be done by lifting the user such that the user's feet, forexample, are above the platform/exercise device (as shown in FIG. 16A).The user can then afterward be lowered to contact the treadmill orplatform etc. In other embodiments, the user is lifted and weighed whilethe user's feet contact the platform, treadmill, or bottom of chamber.

As shown in FIG. 16B, a user may gain access to the motorized lift 900shown in FIG. 16A from a wheelchair. For example, an access assistdevice such a wheelchair ramp 2500 with a contoured 2504 side to fitover the deflated collapsed chamber material 2503 and a lip 2506spanning across a portion of the chamber 2503 to the opening 2550 can beused to wheel the user to over the opening 2550. Once in position, theuser 2502 can drop his feet into the opening 2550 and maneuver off thewheelchair into the chamber 2503. The user 2502 may be able to sit inthe seal interface 2552 and put on a wearable harness such as the userconnection 907. In some embodiments, a motorized lift 900 can then beused to maneuver the user into a substantially upright position as shownin FIG. 16A.

In additional embodiments, the access assist device may be unconnectedto the DAP system. In such embodiments, the user may be bedridden in aseparate location from the DAP system. The user may need to be movedfrom the bed to an access assist device and then moved to the chamberfor therapy. FIGS. 17A-19 show exemplary embodiments where the accessassist device is a moveable unit that can transport the patient to theDAP system. FIGS. 17A-17C show a multi-link arm lifter 1700 that can beconnected to the user body to lift and carry the user to the chamber.The device 1700 shown in FIGS. 17A-17C includes an engagement portion1708 that connects to the user 1702 to support the user 1702 duringmovement from one location to the DAP system. The device 1700 may bepowered manually or automatically suitable operating means such as apneumatic, hydraulic, or mechanical mechanism. The device 1700 may alsobe mobile, such as including wheels 1710 to allow the assist device toroll to a user location, pick up the user, and then bring the user tothe DAP system for drop-off. The device 1700 can also be used to liftthe user into and out of the chamber 1704 via opening 1706. In someembodiments, the lifter 1700 includes an engagement portion thatsupports the user 1702 from under the user's arms (e.g. thoracicsupport). As shown in FIG. 17B, the lifter 1700 has an extendable lengthto accommodate varying distances. For example, in a non-extended state,the device 1700 in FIG. 17A can approach a wheelchair and lift a user1702. In the extend state, shown in FIG. 17B, the lifter 1700 canposition the user 1702 into the opening 1706 and on an exercise device1705 inside the chamber 1704. FIG. 17C provides a top-down view of avariation of device 1700 with a user engagement connection supportingthe user 1702 from under his arms.

Alternatively, the access assist device can be a rolling lifter such asthe one shown in FIGS. 18A-18B where the device 1800 has a patient/userconnector 1808 to hold the user 1802 when the user 1802 is in theconnector 1808, a height-adjustable frame 1806 to allow the user 1802 tobe raised and lowered, and wheels 1810 to permit movement. The device1800 may also be angularly adjusted to accommodate the user's 1802positioning into and out of the user connection 1808. The device 1800may also include a harness 1804 for supporting the user 1802 as thedevice 1800 is moved angularly, vertically, or horizontally (e.g.rolling). FIG. 18B shows a top-down view of the user 1802 in theengagement portion 1808 where the user connection 1808 is a circularcomponent for underarm support. Alternatively, the user connection 1808can be designed to support the user's 1802 waist or torso region.

In an additional embodiment, FIG. 19 shows an overhead suspension system1900 with harness 1904 and wheels 1910 that is moveable from the user'slocation to a DAP system. The device 1900 can include a harness system1904 designed to be worn by the user 1902. Although shown as lifting theuser 1902 from behind, the access assist devices can be used to lift auser 1902 from any direction needed. For example, access to bed-riddenpatient may be limited and require the device 1900 to lift the user 1902from the sides or the end of the bed rather than from behind. The device1900 can include extension components 1906 to accommodate varyingmovement distances. The device 1900 can also continue to be connected tothe user 1902 even while the user is in the DAP system and on anexercise device 1908. In some embodiments, the device 1900 continues toprovide support to the user 1902 while the DAP system is operating, inother embodiments, the device 1900 provides no support to the user 1902once the user is in the chamber.

In further embodiments, the access assist device may not utilize alifting mechanism to transport the user to the DAP system. For example,FIG. 16B shows a ramp system where a wheelchair can be rolled intoproximity of an opening 2550 in the chamber and the user 2502 can slideinto the opening. The ramp system 2500 can be configured to accommodatethe contours and shape of the collapsed chamber by, for example, fittingover a portion of the collapsed chamber material such that the user 2502is positioned directly above the opening 2550. Although FIG. 16Bincludes a motorized lift, in some embodiments, the user 2502 may havesufficient mobility to slide into the opening 2550 and manually raisethe seal frame of the seal interface 2552.

In some embodiments, the access assist devices may also include a loadsensor such as a load cell to measure the weight of the user supportedby the device. For example in the overhead access assist device in FIGS.7A-7E, the DAP system includes load sensors 703 in the base 707 of thesystem and load sensor 701 in the access assist device. The load sensor703 are configured to measure the user's weight exerted against thebottom of the chamber 702 and load sensor 701 measures the user's weightsupported by the access assist device 712. Although the DAP system 300is shown with load sensors in the base 707 of the system, as describedabove, load sensors can be placed in a variety of locations includinghandrails, seal frame, frame assembly, etc.

In addition, FIGS. 17A-17B show the load sensors 1701 at variouslocations on the device 1700. As can be appreciated, the location of theload sensors is variable depending on the device; however, generally aload sensor can be placed near a user load-bearing portion of the device1700. The user connection 1708 is one location where the device 1700bears the weight of the user 1702 when the user 1702 is lifted.Similarly, the power to lift the user may be provided by a motor orpneumatic mechanism. In other embodiments, the load of the user may bederived such as from the amount of power needed to lift the user. FIGS.18A-18B and 19 show load sensors 1801 and 1901 respectively.

In addition to assisting users who have a high degree of motor andmobility impairment, other embodiments are directed toward supportingusers with some but not complete impairment. Users requiring moderatelevels of assistance may not require the use of an access assist devicesuch as an overhead suspension system. Rather, some users may need onlya leaning arm rest or other type of supportive structure in the DAPsystem to allow entering, exiting, and using the DAP system.

FIG. 8A provides an example of one embodiment of the access assistdevice having a supportive structure for use with the DAP system. FIG. 8shows the DAP system of FIGS. 2A-2C outfitted with a support bar 2000.The support bar 2000 is shown to be placed on the frame assembly 320 ofthe DAP system. In FIG. 8A, the support bar 2000 is a horizontal barpositioned across the two side handrails 322 such that a user facingforward can grasp or lean against the support bar 2000.

Moreover, multiple support bars may be used to provide support atdifferent locations of the DAP system depending on the user'sorientation. For example, the support bar may not comprise a singlehorizontal bar but more than one bar where one bar 2002 a is on one sideof the user and one bar 2002 b is on the other side. The bars may have alength less than the width between the sides of the chamber. In oneembodiment, as shown in FIG. 11, support bar 2002 a and support bar 2002b are attached to the frame assembly 320 but do not span across thewidth the space between the handrails 322.

Although shown as part of the handrail 322, the support bar 2000 can beplaced on any of the DAP system components such as frame assemble 320 orseal frame 341 to bear the user's weight. FIG. 8A shows the support bar2000 and 2002 on the frame assembly 320. FIGS. 8B-8C and FIG. 12 showthe support bar 2000 on the seal frame 341. In particular, FIGS. 8B and8C show the support bar 2000 on the seal frame 341 and load sensors1002, 1004 on the DAP system. The support bar 2000, in the depictedembodiment, is a horizontal crossbar designed to engage the hands orarms of a user. The support bar 2000 can be affixed to or removable fromthe seal frame 341. The crossbar may include handgrips to provideadditional support when leaned or grasped by the user. In someembodiments, the support bar 2000 is designed to engage load sensors onthe DAP system. For example, FIG. 8C shows load sensors 1002 on the sealframe 341 under the support bar 2000. When a user applies force on thesupport bar 2000, the load sensors 1002 measure the force and can outputthe measurement to a processor on the DAP system. In some embodiments,the processor receives an output signal from the load sensors 1002providing the force measurements. In some embodiments, the user's forceis a compressive force exerted by leaning or pushing against the supportbar 2000. In other variations, the user's force is a tension forcepulling the support bar away from the load sensors 1002.

In addition to the load sensors on the seal frame 341, the DAP system300 can include load sensors 1004 in the base/platform 321 of the DAPsystem. The load sensors 1004 may be placed under an exercise device1001 (e.g. treadmill). In other embodiments, the load sensors 1004 maybe placed in the exercise device, such as under a treadmill runway belt.In some embodiments, four load sensors are placed at the four corners ofa treadmill in the DAP system. In further embodiments, the processor ofa DAP system receives the load output from load sensors 1004 andsubtracts the load of the exercise device from the total load for theweight of the user exerted against the load sensors 1004.

As described, the support bar may be permanently affixed or removablefrom the DAP system. FIG. 9 provides an example of a removable supportbar 2000 and a corresponding receiver 2001 on the DAP system. In suchembodiments, the DAP system may have a frame assembly with a receivingmeans 2001 to receive and attach the support bar 2000 to the system.Such receiving means may include an attachment mechanism where thesupport bar snaps or clips into place with a mated interface. Othermechanisms include a groove or a slot designed to accommodate thesupport bar's dimensions. Still other examples include a strap or VELCROmechanism to releasably fix the bar to the system. FIG. 9 shows areceiver with a curved semi-flexible elastic component to accommodatethe shape of the support bar 2000. The support bar 2000 may be attachedto the DAP system by pushing the support bar 2000 against the flexiblecomponent of the receiver 2001 to increase the diameter of the curvedpiece. The flexible component widens to accept the support bar 2000 andholds the support bar 2000 in place. In other embodiments, the receiver2001 may retain the support bar 2000 by a locking mechanism such asmated locks or straps.

FIG. 9 also shows that the support bar includes electrical connectors2009 to connect with the receiver at 2007. In some embodiments, thesupport bar 2000 can generate a signal to the processor via the receiverconnection 2007 to indicate that the support bar 2000 is engaged with ordisengaged from the receiver 2001.

In further embodiments, the support bar 2000 has an embedded load sensor2005 to measure the force exerted against the bar. The load measured bysensors 2005 may be transmitted to the processor via the electricalconnections 2009 and 2007. In other embodiments, the support bar (andits sensors) can communicate wirelessly with the processor.Alternatively, the load sensors may be embedded in the receivers. FIG.10 shows a support bar without a load sensor and a receiver 2001 withload sensor 2003. As the user exerts force against the support bar inthe receiver 2001, the load sensor 2003 in receiver 2001 measures theforce and transmits the measurements to the processor.

In addition to the load sensor 2003, the support bar 2000 may includeother sensors for tracking the patient's use of the DAP system. Otherfeatures, such as a heart rate sensor, temperature, blood oxygencontent, may also be separately measured and communicated by the supportbar 2000. In some variations, the support bar is equipped with datastorage capacity such that the support bar can retain useridentification and training or therapy information. For example, thesupport bar can be programed with the user's identification and to keeptrack of the patient's therapy or training protocol. When the patientuses a different DAP system with the same support bar, the DAP systemcan retrieve the protocol and provide the patient with the same trainingwithout having to re-enter the parameters of the therapy.

In further embodiments, other access assist devices may include an armleaning structure 3001 where a portion of the device is inside thechamber. For example, FIGS. 13A-13C shows a DAP system 3000 with achamber 3002, and an arm leaning structure 3001. The bag is removed forclarity in each of these views. A portion of the structure 3001 residesinside the chamber and a portion is outside the chamber 3002. Thetransition point between inside/outside the controlled pressureenvironment within the bag and ambient is provided by a suitably sealedbearing. A portion of the frame is removed in FIG. 13A to show pressureseal bearing 3051 provided for this purpose. The user can lean againstthe structure 3001 for support during calibration. The structure 3001may include a set of handles 3013 a-b for the user to lean or pressagainst to support the user's weight. The structure 3001 may also be incommunication with a load sensor to measure the force exerted on thestructure by the user.

As shown in FIGS. 13A-13C, the handles 3013 a-b are within reach of theuser and the arm leaning structure distal end 3053 is mounted to thetreadmill 3011. While the arm leaning structure or device may beattached in a number of different locations on the treadmill 3011, theembodiments of FIGS. 13A, 13B and 13C illustrate the distal end 3053being supported by the treadmill frame 3055. In each of theseembodiments, load cells 1004 under the treadmill 3011 would measure theweight of the user leaning against handles 3013 a-b for support. Inaddition to the support structure 3001, the embodiments in FIGS. 13A and13C also include handgrips with load cells 1002 in the user seal frame341 to provide another load-bearing and measuring location on the DAPsystem. Additionally or alternatively, FIG. 13B shows a supportstructure 3001 with handles 3013 a-b and a crossbar 2000 in contact withload sensors 1002. The crossbar 2000 may be any of the alternative crossbar or support bar embodiments described herein.

In other alternative embodiments, the load sensor in communication withthe structure 3001 may be placed in a configuration different than theconfiguration illustrated in FIGS. 13A-13C. FIGS. 13D and 13E illustratealternative load cell configurations based on modifications to theenlarged portion of FIG. 13A. The embodiments of FIG. 13D and 13E aresimilar to FIGS. 13A-C in all respects except for these variations inload cell configurations. FIG. 13D illustrates an enlarged portion ofdistal end 3053 in a variation of the system of FIG. 13A. FIG. 13Dincludes a support plate 3057 that is coupled to the load cells 1004.The support plate 3057 permits the use of the load cells 1004 whilepermitting treadmill frame movement independent of the support providedfor the structure 3001. The result of this configuration is that anyload applied to the structure 3001 is transferred to the plate 3057 andregistered by the load cell and controller for use in the calibrationprogram and use of the DAP system.

FIG. 13E illustrates another option for the use of support structure3001 without relying on the treadmill frame as in FIGS. 13A-13C. FIG.13E is an enlarged portion of distal end 3053 as in FIG. 13A thatincludes an additional load cell 1005. The separate load cell 1005 iscoupled to the distal end 3053. As such, any load applied to thestructure 3001 is transferred to the load cell 1005 and registered bythe controller (along with readings from other load cells) for use inthe calibration program and use of the DAP system. While the abovedescribed embodiments describe a single load cell, it is to beappreciated at one or more load cells may be used to perform aparticular function as well as providing separate dedicated load cellsfor the distal end 3053 of each one of the supports with handles 3013 a,3013 b.

In another variation, the supportive structure is an overhead pull-upbar whereby the user can support a part of his weight by holding ontothe bar.

In addition the embodiments described, other variations contemplatedprovide for a method of calibrating a DAP system for a mobility impaireduser. As discussed above, DAP systems provide optimal training andtreatment when the system is calibrated for the specific user. In thepast, calibration required that the user stand still in the DAP systemwhile measurements of weight and pressure were obtained. This is nearimpossible for individuals with impaired mobility and motor abilities.As such, the use of the access assist devices described can also provideassistance as calibration devices for calibration of the DAP system fordisabled individuals.

FIG. 15 provides a flowchart showing calibration of the DAP system withan access assist device. At 4002, the user is positioned in the chamberusing an access assist device. This may be carried by, for example,lifting the user into the chamber with an overhead suspension system orsupporting the user in the chamber with a supportive bar (or both). Oncethe user is in the chamber, the chamber is sealed around the user at4004. Then a first weight value is measured at a predetermined pressureat 4006. This may be the user's weight at ambient pressure or the user'sweight at a positive pressure in the sealed chamber. The user's weightis determined by the total load supported by the access assist deviceand the chamber. This is generally measured by the load sensors on theaccess assist device and in the chamber. For example, a DAP system mayhave load sensors in the platform or base of the chamber and loadsensors in the handrails or a supportive bar attached to the frameassembly. The user may exert weight against the platform as well as thehandrails or support bar. As such, the total weight of the user at apressure point is the combined total load supported and measured by theload sensors. At 4006, the total load supported by the access assistdevice and the chamber is measured by the load sensors and communicatedto the processor. This is repeated at least once at 4008 for anotherpressure point. Once the processor has at least two pressure andcorresponding weight inputs, the processor can calibrate the systemaccording to the described methods above 4010. Briefly, the processorcan generate a pressure weight relationship and operate the DAP systemaccording to that relationship.

In some variations, the calibration is done by taking on the load valuesfrom a subset of the load sensors available. For example, if the load ofthe user is substantially completely supported by the access assistdevice (such as an overhead lifter) then the load value of the sensorattached to the assist device is used to generate a pressure weightrelationship. Alternatively, if the load of the user is primarilysupported by the DAP system and not by an access assist device, thecalibration method may ignore the load sensors of the access assistdevice. In order to determine which load sensor values to take intoaccount for calibration, the processor may run an initial review of theload sensor values measured at a time or pressure point to eliminatenegligible or null values.

In other embodiments, calibrating the DAP system includes a negationstep where the load measured by the DAP system or load sensors prior touse with a user is measured and subtracted from the load measure by theDAP system or load sensors while the user is in the DAP system. As canbe appreciated, in some embodiments, the load sensors may register andmeasure the load of the system or the access assist device even where nouser is present. A load sensor placed under an exercise device such atreadmill may measure the weight of the treadmill in addition to theweight of a user on the treadmill in the chamber. Accordingly, in someembodiments, the load of the DAP system and access devices without auser may be subtracted from the load of the system and devices with auser. For a given load sensor this relationship may be described as:

L_(T(total load with user)) −L_(WU(load without user/baseline measurement)) =L_(U(user load supported))

FIGS. 20 and 21 provide examples of negation steps according embodimentscontemplated. In FIG. 20 system is calibrating by first measuring theload of the DAP Chamber prior to use by a user. The load can be themeasurements registered by load sensors in the frame assembly or thebase of the DAP system. The load can be measured at any pressure,including ambient pressure. This baseline load measurement/reading canbe transmitted and stored by a DAP systems processor or separatelyentered/inputted as part of the operating the DAP system with the user.After a baseline measurement is obtained, the user can be positionedinto and sealed in the chamber. A second load measurement is taken forthe total load measured by the load sensors (which reflects the loadsupported by the system and any access assist device). This second loadmeasurement would include the user's weight as well as the baselineweight. To obtain the weight of the user, the baseline weight can bededucted from the second load measurement. In some embodiments, theprocessor is configured to receive output signals from the load sensorswith the baseline and total measurements. The processor can then deductthe baseline measurement from the total to obtain the user's weight at apressure point. This process can be repeated with at least one otherpressure point to create a pressure weight relationship for the specificuser.

In other embodiments, as shown in FIG. 21, the load sensors may bezeroed (e.g. tare) before a user applies weight to the sensors. The useris then placed into the chamber and sealed into the DAP system. The loadof the user is then measured at least two pressure points to generate apressure weight relationship.

In some embodiments, the access assist device may provide weight supportprior to calibration but no weight support either during or aftercalibration. For example, the overhead suspension system of FIGS. 7A-7Ecan lift and move a user into the chamber 702. Once the user is placedinto the chamber, the suspension system may be configured to releasetension and discontinue supporting the user's weight. In suchcircumstances, the user may be able to bear his weight standing orleaning in the chamber during calibration and operation of the DAPsystem. Once the user is done with the session, the suspension systemmay re-tension to lift the user out of the chamber 702.

Alternatively, in other embodiments, the access assist device, such asthe suspension system, if present during therapy is operated to providestabilization for the patient while using the DAP system. In oneembodiment, the patient is one with compromised trunk control or upperbody strength. Stabilizing may be provided by supporting the userwithout substantially supporting the user's weight. For example, theaccess assist device may be an overhead suspension system with a harnessthat lifts the user from a location outside the chamber. Once the useris in the chamber, the suspension system can continue to provide supportthat does not substantially offset the user's weight in the chamber.This can be done, in some embodiments, where the suspension systemmaintains lateral support to help keep the user upright in the chamberwithout lifting the user off the bottom of the chamber. Additionally,the harness system may provide some support to help the user maintainbalance in the chamber without substantially offsetting the user'sweight. In such cases, the calibration of the DAP system may ignore anynegligible load measured by the suspension.

Alternatively, in other embodiments, the suspension system continues toprovide weight support even after the user has been placed into thechamber (e.g. after calibration). In such cases, the DAP system may beconfigured to allow the system to apportion the weight of the userbetween the suspension system (or other access assist device) and thechamber. The system, via a processor, for example, can monitor the loadmeasured by load sensors and apportion the user's actual weight duringtherapy. For example, 60% of the user's weight may be supported by thepressure chamber and 40% by the suspension device.

In further embodiments, the processor, such as that shown in FIG. 1A canmonitor the load supported by various load sensors 141, 143, and 145 todetermine the percentage of the user's weight supported at the variouslocations. The system can further regulate the pressure of the chamberand the support provided by the access assist device (e.g. tension ofthe suspension system) to apportion the weight among these and otherlocations.

While the embodiments have been described generally as being calibratedand used for individuals with impaired mobility, the description aboveis not limited to improving only the mobility or motor skills of a user.Individuals with any impairment, neurological, physical, or mental canalso benefit from the described embodiments. For example, embodimentsdescribed can be calibrated and used for any user having difficultystanding upright in a DAP system during calibration and treatment.Described systems can be used to treat decreased mobility resulting frommusculoskeletal conditions such as sprains or bone fractures or fromneurological conditions such as neurological injury (e.g. from stroke),neurodegenerative conditions (e.g. Alzheimer's or Parkinson's Disease),or traumatic brain injury (TBI). In some embodiments, a user may betreated by DAP therapy in order to regain motor skills that have beendamaged or diminished by a physical injury such as muscle atrophy frombone fracture treatment. In other cases, the patient may be improvingnon-motor functions such as cardiovascular circulation by allowing thepatient to move from a prone to a substantially upright position.Similarly, a disabled patient may have increased water retention in, forexample, lower limbs. The DAP system and access devices described canprovide such a patient the ability to stand substantially upright and toexercise their limbs to help remove excess fluid. Similarly, the DAPsystem and access devices may be used to help improve mobility for obeseor morbidly obese users who wish to exercise but are not physically fitenough to bear their entire weight during exercise.

In further embodiments, the users may be healthy but require assistancein standing upright in the DAP system during therapy. For example,pregnant women are often counseled by healthcare providers to exerciseduring pregnancy. However, rapid weight gain and changing bodyconditions often make simple activities like walking unbearable. The DAPsystems and access devices described can be used to provide exercise andphysical therapy to healthy individuals who need some assistance forexercise.

In some embodiments, a method for improving cardiovascular andrespiratory function of user includes first transporting a disabled userinto a DAP system. This can be by way of an access assist device such asthe overhead suspension systems or wheelchair ramp described. Once inthe DAP chamber, the user can be supported by a support bar or otherload-bearing support device. The system is then calibrated for the useraccording to the methods described above. Once calibrated, the DAPsystem can provide treatment by regulating the pressure in the chambersuch that a portion of the user's weight is offset by positive pressure.The user can remain in the chamber for treatment as long as needed forimproving cardiovascular and respiratory function. In some embodiments,the DAP system may include sensors to monitor the user's vital signsduring treatment to allow for adjustments if necessary.

In other embodiments, a method of improving cardiovascular function in auser with compromised lower body function, comprising lifting the userwith compromised lower body function; lowering and sealing the user intoa pressure chamber of a differential pressure system; supporting aportion of the user's body to assist in accommodating the degree ofcompromised lower body function such that the user is substantiallyupright; sealing the pressure chamber; calibrating the differentialpressure system to generate a pressure-weight relationship; andregulating the pressure in the chamber according to the relationship.

Another embodiment provides for a method of improving a stroke patient'motor skills comprising: supporting a portion of the patient's weightwith a calibration device; supporting another portion of the patient'sweight inside a sealed pressure chamber; sealing the chamber around anarea of the patient's body; calibrating the differential pressuresystem; and regulating the pressure in the chamber according to therelationship.

Although the components of the DAP systems and the access assist deviceshave been described in certain locations, these embodiments andillustrations are not intended to be limiting. As can be appreciated,for example, any number of combination or positions for the load sensorson the DAP systems and access assist devices are possible. For instance,any number of load sensors can be placed in any number of suitablelocations in the systems and devices described. A load sensor can beplaced in the base on the chamber, in the seal interface, in the accessassist device, on a supportive structure, on a frame assembly, etc. Loadsensors may be placed above or below a user as shown in FIGS. 2A-2C,FIGS. 7A-7E, and FIGS. 13A-13F. Load sensors may be attached to the DAPsystem directly, see FIGS. 2A-2E or via another component such as thosesensors 2005 shown in FIG. 9. Additionally, multiple load sensors may beplaced in common or different locations suitable for measuring theuser's weight. It is to be appreciated that the load sensors used indescribed embodiments may be used in a wide variety of alternativeconfigurations and combinations. Exemplary load cell combinations orconfigurations include load sensors above the user, 141, below the user(e.g. below torso or lower extremities), 145.

While embodiments have been described and presented herein, theseembodiments are provided by way of example only. Variations, changes andsubstitutions may be made without departing from the embodiments. Itshould be noted that various alternatives to the exemplary embodimentsdescribed herein may be employed in practicing the embodiments. For allof the embodiments described herein, the steps of the methods need notto be performed sequentially.

Although the embodiments herein have been described in relation tocertain examples, various additional embodiments and alterations to thedescribed examples are contemplated within the scope of the invention.Thus, no part of the foregoing description should be interpreted tolimit the scope of the invention as set forth in the following claims.For all of the embodiments described above, the steps of the methodsneed not be performed sequentially. Accordingly, it is not intended thatthe invention be limited, except as by the appended claims.

1. A differential pressure system for improving mobility of a disabledindividual, comprising: a pressure chamber with a seal interfaceconfigured to receive a portion of a disabled user's body and to form aseal between the user's body and the chamber, the chamber configured toapply pressure to the portion of the user's body while the user's bodyis sealed in the chamber; a platform in the pressure chamber, whereinthe platform is configured to contact the user's body; a first loadsensor positioned substantially underneath the user's torso andconfigured to measure the load applied by the user while the user is inthe chamber and to provide an output signal; a second load sensorcoupled to the differential pressure system at a position that isdifferent from the first load sensor, the second load sensor configuredto provide an output signal; a processor configured to receive theoutput signals from the load sensors and to calibrate the system for useby the disabled user by generating a relationship between pressure inthe chamber and actual weight of the user while the user is sealed inthe chamber, wherein the actual weight of the user is the total weightof the user measured by the first and second load sensors at pressurepoints, the processor regulating the pressure of the chamber accordingto said relationship.
 2. The system of claim 1 the system furthercomprising an access assist device configured to assist the disableduser's access to the chamber, wherein the second load sensor is incommunication with the access assist device.
 3. The system of claim 2,wherein the second load sensor is positioned on the access assistdevice.
 4. The system of claim 2, wherein the access assist device isconfigured to bear a portion of the user's weight during calibration. 5.The system of claim 2, wherein the access assist device is configured tobear substantially all of the user's weight during calibration.
 6. Thesystem of claim 1, further comprising a plurality of load sensorssubstantially underneath the user's torso and a plurality of loadsensors coupled to the differential pressure system at one or morelocations above the user's lower extremities.
 7. The system of claim 1,wherein the first load sensor is positioned within the pressure chamberand is configured to engage the portion of the user's body in thepressure chamber, and the second load sensor is positioned outside thepressure chamber and is configured to engage the user's body outside thepressure chamber.
 8. The system of claim 1, further comprising anexercise device, wherein the exercise device is a treadmill.
 9. Thesystem of claim 6, wherein calibrating the system comprises an actualweight of the user provided by the total user weight measured by theplurality of load sensors at a pressure point.
 10. The system of claim1, wherein the total weight of the user is determined by summing theload measured by the first and second sensors and subtracting a baselineload measurement from the sum.
 11. The system of claim 1, the systemfurther comprising a handrail outside the pressure chamber wherein thehandrail is configured to bear a portion of the user's weight and thesecond load sensor measures the amount of the user's weight supported bythe handrail during calibration.
 12. The system of claim 1, the systemfurther comprising a seal interface frame supporting the seal interfaceof the pressure chamber and configured to support at least a portion ofthe weight of the user, wherein the second load sensor measures theamount of the user's weight supported by the seal interface frame duringcalibration.
 13. The system of claim 1, the system further comprising aframe assembly, wherein the frame assembly bears a portion of thedisabled user's weight during calibration and the second load sensormeasures the amount of the user's weight supported by the frame assemblyduring calibration.
 14. The system of claim 1, wherein the access assistdevice comprises an overhead suspension device.
 15. The system of claim2, wherein the access assist device is a handrail.
 16. The system ofclaim 2, wherein the access assist device is a motorized lift.
 17. Thesystem of claim 2, wherein the access assist device is a support barthat is removably attachable to a frame on the system.
 18. The system ofclaim 17, wherein the support bar comprising an attachment mechanism toremovably attach and detach the bar from the frame.
 19. The system ofclaim 17, wherein the support bar outputs a measured load signal to theprocessor.
 20. The system of claim 17, wherein the support bar isconfigured to store user-related data.
 21. The system of claim 17, thesystem further comprising a support bar receiver, wherein the supportreceiver is configured to measure the weight of the user exerted againstthe support bar while the support bar is attached to the system.
 22. Thesystem of claim 1, wherein at least one load sensor is configured tocommunicate wirelessly with the processor.
 23. The system of claim 1,wherein at least one load sensor is configured to communicate with theprocessor via a wired connection.
 24. The system of claim 1, wherein atleast one load sensor is positioned on the seal interface of thechamber.
 25. The system of claim 6, wherein the plurality of loadsensors coupled to the system above the user's lower extremities arepositioned on the system at a distance within the user's arm span.
 26. Adifferential pressure system for improving mobility of a disabledindividual, comprising: a pressure chamber with a seal interfaceconfigured to receive a portion of a disabled user's body and to form aseal between the user's body and the chamber, the chamber configured toapply pressure to the portion of the user's body while the user's bodyis sealed in the chamber; an exercise device placed in the pressurechamber, wherein the exercise device is configured to contact the user'sbody while the exercise device is in operation; at least one load sensoron the exercise device, the load sensor configured to measure the loadapplied by the user to the exercise device while the user is in thechamber and to provide an output signal; at least one load sensor not onthe exercise device and positioned on the differential pressure systemabove the user's lower extremities, the load sensor configured toprovide an output signal; a processor configured to receive the outputsignals from the load sensors and to calibrate the system for use by thedisabled user by generating a relationship between pressure in thechamber and actual weight of the user while the user is sealed in thechamber, wherein the actual weight of the user is the total user weightmeasured by the load sensors at pressure points, the processorregulating the pressure of the chamber according to said relationship.27. The system of claim 26, wherein the exercise device is a treadmillcomprising a runway belt and the load sensor on the exercise device isunder the runway belt.
 28. The system of claim 26 further comprising anaccess assist device, wherein the load sensor not on the exercise deviceis positioned on the access assist device.
 29. The system of claim 28,wherein the access assist device is an overhead suspension system. 30.The system of claim 29, wherein the access assist device is a supportbar that is removably attachable to a frame of the system.
 31. Thesystem of claim 26, wherein the load sensors can communicate wirelesslyor through a wired path with the processor.
 32. A method of calibratinga differential pressure system for a disabled user with impairedmobility comprising: supporting at least a portion of the user's weightwith an access assist device having an assist device load sensorconfigured to measure the user's weight supported by the assist device;positioning the user in a pressure chamber; sealing the chamber aroundan area of the user's body; and calibrating the differential pressuresystem for the disabled user based on the total user weight measured bythe load sensor.
 33. The method of claim 32, wherein calibrating furthercomprises calculating the total user weight by subtracting a baselineload measurement from the total load measured by the sensor.
 34. Themethod of claim 32, wherein calibrating further comprises zeroing theload sensor prior to supporting the user's weight.
 35. The method ofclaim 32 further comprising supporting a portion of the user's weightfrom underneath the user's torso while the user is in the chamber, thechamber having a chamber load sensor to measure the supported userweight and calibrating the system based on the total user weightmeasured from the load sensors.
 36. The method of claim 35, wherein thetotal user weight is calculated by subtracting a baseline loadmeasurement from the total load measured by the sensors.
 37. A method ofcalibrating a differential pressure system for a disabled user withimpaired mobility comprising: lifting a user relative to an opening in apressure chamber with an access assist device; lowering the user intothe opening such that a portion of the user's body is in the pressurechamber; sealing the chamber around the portion of the patient's body;outputting a signal from a load sensor in the pressure chamber;outputting a signal from a load sensor coupled to the access assistdevice; and calibrating the differential pressure system for thedisabled user based on the total user weight measured by an output fromthe load sensor in the pressure chamber and an output from the loadsensor coupled to the access assist device.
 38. The method of claim 37,wherein the total user weight is calculated by subtracting a baselineload measurement from the total load measured by the load sensors whilethe user is sealed in the chamber.
 39. A differential pressure systemfor improving the mobility of a disabled individual comprising: apressure chamber with a seal interface configured to receive a portionof a disabled user's body and to form a seal between the user's body andthe chamber, the chamber configured to apply pressure to the portion ofthe user's body while the user's body is sealed in the chamber; anexercise device placed in the pressure chamber, wherein the exercisedevice is configured to contact the user's body while the exercisedevice is in operation; a load sensor coupled to the exercise device,the load sensor configured to measure the weight applied by the user tothe exercise device while the user is in the chamber and to provide anoutput signal for weight measurements; a calibration device configuredto measure the weight of the user's body exerted outside the pressurechamber, the calibration device providing an output signal for weightmeasurements; and a processor configured to receive the output signalsfrom the load sensor and the calibration device to calibrate the systemfor use by the disabled user by generating a relationship betweenpressure in the chamber and actual weight of the user while the user issealed in the chamber, wherein the actual weight of the user is thetotal user weight measured by the load sensor and the calibration deviceat pressure points, the processor regulating the pressure of the chamberaccording to said relationship.
 40. The system of claim 39, wherein thecalibration device is a support bar configured to removably attach tothe system outside the pressure chamber.
 41. The system of claim 39,wherein the calibration device comprises a load sensor.
 42. The systemof claim 39, wherein the calibration device supports a portion of theuser's weight during calibration.
 43. A differential air pressure systemcomprising: a positive pressure chamber with a seal interface configuredto receive a portion of a user's body and form a seal between the user'sbody and the chamber; a lift access device comprising a hoist device anda load sensor, wherein the load sensor outputs a load measurement whenlifting a user; a load sensor attached a bottom portion of the pressurechamber, wherein the load sensor outputs a load measurement when a useris in the sealed chamber; and a processor configured to calibrate thesystem by receiving the load measurements from the load sensors,calculating the total user weight supported by the lift access deviceand chamber at pressure points, and generating a pressure weightrelationship.
 44. The system of claim 43 further comprising aninterlocking mechanism configured to engage with the lift access device,wherein the processor is configured to engage the interlocking mechanismto stop movement of the lift access device.
 45. The system of claim 44,wherein the interlocking mechanism comprises at least one interlockcheckpoint at which the interlocking mechanism can engage if the chamberis not configured to receive the user.
 46. A method of calibrating adifferential pressure system for a disabled user with impaired mobility:supporting a portion of the user's weight with a calibration device;supporting another portion of the user's weight inside a sealed pressurechamber; sealing the chamber around an area of the user's body; andcalibrating the differential pressure system for the disabled user basedon the total user weight supported.
 47. The method of claim 46 furthercomprising detecting that the calibration device has been connected tothe system.
 48. The method of 46 further comprising detecting that thecalibration device has been disengaged from the system.
 49. A method ofimproving cardiovascular function in a user with compromised lower bodyfunction, comprising: lifting the user with compromised lower bodyfunction; lowering and sealing the user into a pressure chamber of adifferential pressure system; supporting a portion of the user's body toassist in accommodating the degree of compromised lower body functionsuch that the user is substantially upright; sealing the pressurechamber; calibrating the differential pressure system to generate apressure-weight relationship; and regulating the pressure in the chamberaccording to the relationship.
 50. A method of improving a strokepatient's motor skills comprising: supporting a portion of the patient'sweight with a calibration device; supporting another portion of thepatient's weight inside a sealed pressure chamber; sealing the chamberaround an area of the patient's body; calibrating the differentialpressure system; and regulating the pressure in the chamber according tothe relationship.